Hi everybody!

The reason from this post is to get some help with my program, which is a tic tac toe game. The objective of the program is to make a game between the computer and the human player, in which the player always lose.
The problem is that the computer is marking the X two times in the computer's turn I don't know why it happened.
Could you please help me?

import java.awt.*;
import java.awt.event.*;
import java.applet.*;
import java.lang.Math.*;
 
public class gato2 extends Applet implements ActionListener{
	private Button un, deux, trois, quatre , cinq, six, sept, huit, neuf,one,two, three, four, five,six6,seven,eight,nine, AC,start;
	private int x,y,z, uno = 0, dos = 0, tres = 0, cuatro = 0, cinco =0, seis =0, siete =0, ocho=0, nueve=0,k,a2,a3,a4,a5,a6,a7,a8,a9,ac=0,inic=0, um=0, dois=0,três=0, quatro=0, cinco5=0, seis6=0, sete=0, oito=0, nove=0, c0,c2,c3,c4,c5,c6,c7,c8,c9;
	public Panel a1,b1,c1,start1;
 
	public void init (){
 
	setLayout(new FlowLayout());
	a1 = new Panel (new GridLayout (3,3));
	b1 = new Panel (new GridLayout (1,1));
	c1 = new Panel (new GridLayout (3,3));
	start1= new Panel (new GridLayout(1,1));
 
	start= new Button("Inicio");start.setBackground(Color.green);start.setForeground(Color.WHITE);
	un= new Button("1");un.setBackground(Color.BLACK);un.setForeground(Color.WHITE);
	deux = new Button("2");deux.setBackground(Color.BLACK);deux.setForeground(Color.WHITE);
	trois = new Button("3");trois.setBackground(Color.BLACK);trois.setForeground(Color.WHITE);
	quatre = new Button("4");quatre.setBackground(Color.BLACK);quatre.setForeground(Color.WHITE);
	cinq = new Button("5");cinq.setBackground(Color.BLACK);cinq.setForeground(Color.WHITE);
	six = new Button("6");six.setBackground(Color.BLACK);six.setForeground(Color.WHITE);
	sept = new Button ("7");sept.setBackground(Color.BLACK);sept.setForeground(Color.WHITE);
	huit = new Button ("8");huit.setBackground(Color.BLACK);huit.setForeground(Color.WHITE);
	neuf = new Button ("9");neuf.setBackground(Color.BLACK);neuf.setForeground(Color.WHITE);
	one = new Button ("1");one.setBackground(Color.blue);one.setForeground(Color.WHITE);
	two = new Button ("2");two.setBackground(Color.blue);two.setForeground(Color.WHITE);
	three = new Button ("3");three.setBackground(Color.blue);three.setForeground(Color.WHITE);
	four = new Button ("4");four.setBackground(Color.blue);four.setForeground(Color.WHITE);
	five = new Button ("5");five.setBackground(Color.blue);five.setForeground(Color.WHITE);
	six6 = new Button ("6");six6.setBackground(Color.blue);six6.setForeground(Color.WHITE);
	seven = new Button ("7");seven.setBackground(Color.blue);seven.setForeground(Color.WHITE);
	eight = new Button ("8");eight.setBackground(Color.blue);eight.setForeground(Color.WHITE);
	nine = new Button ("9");nine.setBackground(Color.blue);nine.setForeground(Color.WHITE);
	AC = new Button ("AC");AC.setForeground(Color.black);
 
	add(start1);
	add(a1);
	add(b1);
	add(c1);
	start1.add(start);
	a1.add(un);
	a1.add(deux);
	a1.add(trois);
	a1.add(quatre);
	a1.add(cinq);
	a1.add(six);
	a1.add(sept);
	a1.add(huit);
	a1.add(neuf);
	b1.add(AC);
	c1.add(one);
	c1.add(two);
	c1.add(three);
	c1.add(four);
	c1.add(five);
	c1.add(six6);
	c1.add(seven);
	c1.add(eight);
	c1.add(nine);
 
	start.addActionListener(this);
	un.addActionListener(this);
	deux.addActionListener(this);
	trois.addActionListener(this);
	quatre.addActionListener(this);
	cinq.addActionListener(this);
	six.addActionListener(this);
	sept.addActionListener(this);
	huit.addActionListener(this);
	neuf.addActionListener(this);
	AC.addActionListener(this);
	one.addActionListener(this);
	two.addActionListener(this);
	three.addActionListener(this);
	four.addActionListener(this);
	five.addActionListener(this);
	six6.addActionListener(this);
	seven.addActionListener(this);
	eight.addActionListener(this);
	nine.addActionListener(this);
 
	}
 
	public void actionPerformed(ActionEvent e) {
				Object fuente = e.getSource();
k=0;
 
 
							if(fuente==start){
							inic=1;
							}
 
							if(fuente== deux){
							dos=2;
							}
 
							if(fuente== trois){
							tres=3;
 
						    }
 
							if(fuente== quatre){
							cuatro=4;
 
							}
 
							if(fuente== cinq){
							cinco=5;
 
							}
 
							if(fuente== six){
							seis=6;
 
							}
 
							if(fuente== sept){
							siete=7;
 
							}
 
							if(fuente== huit){
							ocho=8;
 
							}
 
							if(fuente== neuf){
							nueve=9;
 
							}
 
							if(fuente== one){
							um=1;
							}
 
							if(fuente== two){
							dois=2;
							}
 
							if(fuente== three){
							três=3;
							}
 
							if(fuente== four){
							quatro=4;
							}
 
							if(fuente== five){
							cinco5=5;
							}
 
							if(fuente== six6){
							seis6=6;
							}
 
							if(fuente== seven){
							sete=7;
							}
 
							if(fuente== eight){
							oito=8;
							}
 
							if(fuente== deux){
							nove=9;
							}
 
							if(fuente== AC){
								uno = 0;
								dos = 0;
								tres = 0;
								cuatro = 0;
								cinco =0;
								seis =0;
								siete =0;
								ocho=0;
								nueve=0;
								um=0;
								dois=0;
								três=0;
								quatro=0;
								cinco5=0;
								seis6=0;
								sete=0;
								oito=0;
								nove=0;
 
								ac=1;
								}
 
repaint();
						}
 
 
	public void paint(Graphics g) {
 
 
 
 
/*botón para borrar*/
 
	 							if (ac==1){
									g.setColor(Color.white);
									g.fillRect(0,0,900,900);
									ac=0;
								}
/*botones para el jugador*/
 
								if(dos==2){
								g.drawOval(275,75,50,50);
								a2=2;
								}
 
								if(tres==3){
								g.drawOval(360,75,49,49);
								a3=3;
								}
 
								if(cuatro==4){
								g.drawOval(185,160,49,49);
								a4=4;
								}
 
								if(cinco==5){
								g.drawOval(275,160,50,50);
								a5=5;
								}
 
								if(seis==6){
								g.drawOval(360,160,49,49);
								a6=6;
								}
 
								if(siete==7){
								g.drawOval(185,250,49,49);
								a7=7;
								}
 
								if(ocho==8){
								g.drawOval(275,250,49,49);
								a8=8;
								}
 
								if(nueve==9){
								g.drawOval(360,250,49,49);
								a9=9;
							    }
 
/*botones computadora*/
 
							    if(um==1){
								g.drawLine(175,75,250,135);
								g.drawLine(250,75,175,135);
								c0=1;
								}
 
								if(dois==2){
								g.drawLine(250,75,350,135);
								g.drawLine(350,75,250,135);
								c2=2;
							    }
 
								if(três==3){
								g.drawLine(350,75,425,135);
								g.drawLine(425,75,350,135);
								c3=3;
							    }
 
							    if(quatro==4){
								g.drawLine(175,135,250,235);
								g.drawLine(250,135,175,235);
								c4=4;
							    }
 
							    if(cinco5==5){
								g.drawLine(250,135,350,235);
								g.drawLine(350,135,250,235);
								c5=5;
							    }
 
							    if(seis6==6){
								g.drawLine(350,135,425,235);
								g.drawLine(425,135,350,235);
								c6=6;
							    }
 
								if(sete==7){
								g.drawLine(175,235,250,300);
								g.drawLine(250,235,175,300);
								c7=7;
							    }
 
							    if(oito==8){
								g.drawLine(250,235,350,300);
								g.drawLine(350,235,250,300);
								c8=8;
							    }
 
							    if(nove==9){
								g.drawLine(350,235,425,300);
								g.drawLine(425,235,350,300);
								c9=9;
							    }
 
/*líneas del gane*/
 
/*diagonales*/
								if((um==1)&&(cinco5==5)&&(nove==9)){
									g.drawLine(175,75,425,300);
								}
 
								if((três==3)&&(cinco5==5)&&(sete==7)){
									g.drawLine(425,75,175,300);
								}
 
/*verticales*/
								if((um==1)&&(quatro==4)&&(sete==7)){
									g.drawLine(212,75,212,300);
								}
 
								if((três==3)&&(seis6==6)&&(nove==9)){
									g.drawLine(387,75,387,300);
								}
 
/*horizontales*/
								if((um==1)&&(dois==2)&&(três==3)){
									g.drawLine(212,105,387,105);
								}
 
 
								if((sete==7)&&(oito==8)&&(nove==9)){
									g.drawLine(175,267,425,267);
								}
 
 
 
 
 
 
							if(inic==1){
 
/*inicio del juego*/
								g.drawLine(250,75,250,300);
								g.drawLine(350,75,350,300);
								g.drawLine(175,135,425,135);
								g.drawLine(175,235,425,235);
/*primera jugada*/
								um=1;
								}
 
 
										if (a2==2){
											cinco5=5;
												if (a3==3){
													nueve=9;
													System.out.println("PERDISTE");
													}
												if(a4==4){
													nove=9;
 
													g.drawLine(175,75,425,300);
													System.out.println("PERDISTE");
													}
												if(a6==6){
 
													nove=9;
 
													g.drawLine(175,75,425,300);
													System.out.println("PERDISTE");
													}
												if(a7==7){
 
													nove=9;
 
													g.drawLine(175,75,425,300);
													System.out.println("PERDISTE");
													}
 
												if(a8==8){
 
													nove=9;
 
													g.drawLine(175,75,425,300);
													System.out.println("PERDISTE");
													}
 
												if(a9==9){
 
													sete=7;
 
 
														if(a4==4){
 
															três=3;
 
															g.drawLine(425,75,175,300);
															System.out.println("PERDISTE");
													}
														if(a3==3){
 
															quatro=4;
 
															g.drawLine(212,75,212,300);
															System.out.println("PERDISTE");
													}
														if(a6==6){
 
															quatro=4;
 
															g.drawLine(212,75,212,300);
															System.out.println("PERDISTE");
													}
														if(a8==8){
 
															quatro=4;
 
															g.drawLine(212,75,212,300);
															System.out.println("PERDISTE");
													}
													}
													}
 
												if (a3 == 3){
 
 
													sete=7;
 
 
														if (a2 ==2){
 
															quatro=4;
 
															g.drawLine(212,75,212,300);
															System.out.println("PERDISTE");
																}
 
														if (a5 ==5){
 
															quatro=4;
 
															g.drawLine(212,75,212,300);
															System.out.println("PERDISTE");
																}
 
														if (a6 ==6){
 
															quatro=4;
 
															g.drawLine(212,75,212,300);
															System.out.println("PERDISTE");
																}
 
														if (a8 ==8){
 
															quatro=4;
 
															g.drawLine(212,75,212,300);
															System.out.println("PERDISTE");
																}
														if (a9 ==9){
 
															quatro=4;
 
															g.drawLine(212,75,212,300);
															System.out.println("PERDISTE");
																}
 
														if (a4 ==4){
 
															nove=9;
 
 
 
																if (a2 == 2){
 
																	oito=8;
 
																	g.drawLine(175,267,425,267);
																	System.out.println("PERDISTE");
																	}
 
																if (a5 ==5){
 
																	oito=8;
 
																	g.drawLine(175,267,425,267);
																	System.out.println("PERDISTE");
																	}
 
																if (a6==6){
 
																	oito=8;
 
																	g.drawLine(175,267,425,267);
																	System.out.println("PERDISTE");
																	}
 
																if (a8 == 8){
 
																	cinco5=5;
 
																	g.drawLine(175,75,425,300);
																	System.out.println("PERDISTE");
																	}
																	}
																	}
 
												if (a4 == 4){
 
													cinco5=5;
 
														if (a2 ==2){
 
															nove=9;
 
															g.drawLine(175,75,425,300);
															System.out.println("PERDISTE");
															}
														if (a3 ==3){
 
															nove=9;
 
															g.drawLine(175,75,425,300);
															System.out.println("PERDISTE");
															}
														if (a6 ==6){
 
															nove=9;
 
															g.drawLine(175,75,425,300);
															System.out.println("PERDISTE");
															}
														if (a7 ==7){
 
															nove=9;
 
															g.drawLine(175,75,425,300);
															System.out.println("PERDISTE");
															}
														if(a8==8){
 
															nove=9;
 
															g.drawLine(175,75,425,300);
															System.out.println("PERDISTE");
															}
 
														if (a9==9){
 
															três=3;
 
 
																if(a6==6){
 
																	dois=2;
 
																	g.drawLine(175,105,425,105);
																	System.out.println("PERDISTE");
																	}
 
																if (a7==7){
 
																	dois=2;
 
																	g.drawLine(175,105,425,105);
																	System.out.println("PERDISTE");
																	}
 
																if (a8==8){
 
																	dois=2;
 
																	g.drawLine(175,105,425,105);
																	System.out.println("PERDISTE");
																	}
 
																if (a2==2){
 
																	sete=7;
 
																	g.drawLine(425,75,175,300);
																	System.out.println("PERDISTE");
																	}
																	}
																	}
 
 
												if (a5 == 5){
 
													nove=9;
 
															if (a2 == 2){
 
															oito=8;
															g.drawLine(250,300,350,235);
																if (a3==3){
 
																sete=7;
 
																g.drawLine(175,267,425,267);
																System.out.println("Perdiste :P");
																}
																if (a4==4){
 
																sete=7;
 
																g.drawLine(175,267,425,267);
																System.out.println("Perdiste :P");
																}
																if (a6==6){
 
																sete=7;
 
																g.drawLine(175,267,425,267);
																System.out.println("Perdiste :P");
																}
 
																if (a7==7){
 
																três=3;
 
																	if (a4 ==4){
 
																	seis6=6;
 
																	g.drawLine(387,75,387,300);
																	System.out.println("Perdiste! :P");
																	}
 
																	if(a6 ==6){
 
																	quatro=4;
 
																	System.out.println ("Empate :S");
																	}
																	}
																    }
 
															if (a3 ==3){
 
															sete=7;
 
 
																if (a2 ==2){
 
																quatro=4;
 
																g.drawLine(212,75,212,300);
																System.out.println("Perdiste!!!! :)");
																}
 
																if (a8==8){
 
																quatro=4;
 
																g.drawLine(212,75,212,300);
																System.out.println("Perdiste!!!! :)");
																}
 
																if (a4==4){
 
																oito=8;
																g.drawLine(250,300,350,235);
																g.drawLine(175,267,425,267);
																System.out.println("Perdiste!!!! :)");
																}
 
																if(a6==6){
 
																oito=8;
																g.drawLine(250,300,350,235);
																g.drawLine(175,267,425,267);
																System.out.println("Perdiste!!!! :)");
																}
																}
 
 
															if (a4==4){
 
															seis6=6;
 
 
																if(a2==2){
 
																três=3;
 
																g.drawLine(387,75,387,300);
																System.out.println("Perdiste!!!! :)");
																}
																if(a7==7){
 
																três=3;
 
																g.drawLine(387,75,387,300);
																System.out.println("Perdiste!!!! :)");
																}
																if(a8==8){
 
																três=3;
 
																g.drawLine(387,75,387,300);
																System.out.println("Perdiste!!!! :)");
																}
																if (a3==3){
 
																sete=7;
 
																	if (a2==2){
 
																	oito=8;
																	g.drawLine(250,300,350,235);
																	g.drawLine(175,267,425,267);
																	System.out.println("Perdiste!!!! :)");
																	}
																	if (a8==8){
 
																	dois=2;
 
																	System.out.println("Empate :S");
																	}
																	}
																	}
 
															if (a6==6){
 
																		quatro=4;
 
																			if (a2==2){
 
																			sete=7;
 
																			g.drawLine(212,75,212,300);
																			System.out.println("Perdiste :)");
																			}
																			if (a3==3){
 
																			sete=7;
 
																			g.drawLine(212,75,212,300);
																			System.out.println("Perdiste :)");
																			}
																			if(a8==8){
 
																			sete=7;
 
																			g.drawLine(212,75,212,300);
																			System.out.println("Perdiste :)");
																			}
 
																			if (a7==7){
 
																			três=3;
 
																				if (a8==8){
 
																				dois=2;
 
																				g.drawLine(175,105,425,105);
																				System.out.println("Perdiste :)");
																				}
																				if (a2==2){
 
																				oito=8;
																				g.drawLine(250,300,350,235);
																				System.out.println("Empate :S");
																				}
																				}
																				}
 
																		if(a7 ==7){
 
																		três=3;
 
																			if (a2 ==2){
 
																			seis6=6;
 
																			g.drawLine(387,75,387,300);
																			System.out.println("Perdiste :)");
																			}
 
																			if (a8==8){
 
																			seis6=6;
 
																			g.drawLine(387,75,387,300);
																			System.out.println("Perdiste :)");
																			}
 
																			if (a4==4){
 
																			dois=2;
 
																			g.drawLine(175,105,425,105);
																			System.out.println("Perdiste!!!! :)");
																			}
 
																			if(a6==6){
 
																			dois=2;
 
																			g.drawLine(175,105,425,105);
																			System.out.println("Perdiste!!!! :)");
																			}
																			}
 
																		if(a8==8){
 
																		dois=2;
 
																			if(a4==4){
 
																			três=3;
 
																			g.drawLine(175,105,425,105);
																			System.out.println("Perdiste!!!! :)");
																			}
																			if (a6==6){
 
																			três=3;
 
																			g.drawLine(175,105,425,105);
																			System.out.println("Perdiste!!!! :)");
																			}
																			if(a7==7){
 
																			três=3;
 
																			g.drawLine(175,105,425,105);
																			System.out.println("Perdiste!!!! :)");
																			}
 
																			if (a3==3){
 
																			sete=7;
 
																				if (a6==6){
 
																				quatro=4;
 
																				g.drawLine(212,75,212,300);
																				System.out.println("Perdiste!!!! :)");
																				}
 
																				if (a4==4){
 
																				seis6=6;
 
																				System.out.println("Empates, :S");
																				}
																				}
																				}
																				}
 
												if (a6 == 6){
 
														cinco5=5;
 
 
															if (a2 == 2){
 
															nove=9;
 
 
															g.drawLine(175,75,425,300);
															System.out.println("Perdiste!!");
															}
															if (a3==3){
 
															nove=9;
 
 
															g.drawLine(175,75,425,300);
															System.out.println("Perdiste!!");
															}
															if (a4==4){
 
															nove=9;
 
 
															g.drawLine(175,75,425,300);
															System.out.println("Perdiste!!");
															}
															if (a7==7){
 
															nove=9;
 
 
															g.drawLine(175,75,425,300);
															System.out.println("Perdiste!!");
															}
															if (a8==8){
 
															nove=9;
 
 
															g.drawLine(175,75,425,300);
															System.out.println("Perdiste!!");
															}
 
																if(a9==9){
 
																três=3;
 
 
																	if (a2==2){
 
																	sete=7;
 
 
																	g.drawLine(425,75,175,300);
																	System.out.println("Perdiste!!! :D");
																	}
																	if (a4==4){
 
																	dois=2;
 
 
																	g.drawLine(212,105,387,105);
																	System.out.println("Gané!!! Yei!!! :D");
																	}
																	if (a7==7){
 
																	dois=2;
 
 
																	g.drawLine(212,105,387,105);
																	System.out.println("Gané!!! Yei!!! :D");
																	}
																	if(a8==8){
 
																	dois=2;
 
 
																	g.drawLine(212,105,387,105);
																	System.out.println("Gané!!! Yei!!! :D");
																	}
																	}
																	}
												if (a7 == 7){
 
														três=3;
 
 
															if (a4 == 4){
 
																dois=2;
 
																g.drawLine(212,105,387,105);
																System.out.println ("Gané!!! :D");
																}
 
															if(a5==5){
 
																dois=2;
 
																g.drawLine(212,105,387,105);
																System.out.println ("Gané!!! :D");
																}
 
														if(a6==6){
 
																dois=2;
 
																g.drawLine(212,105,387,105);
																System.out.println ("Gané!!! :D");
																}
 
														if(a8==8){
 
																dois=2;
 
																g.drawLine(212,105,387,105);
																System.out.println ("Gané!!! :D");
																}
 
														if(a9==9){
 
																dois=2;
 
																g.drawLine(212,105,387,105);
																System.out.println ("Gané!!! :D");
																}
 
														if (a2==2){
 
																nove=9;
 
 
																if (a4==4){
 
																		seis6=6;
 
																		g.drawLine(387,105,387,267);
																		System.out.println("Perdiste!!! =)");
																		}
 
																if(a5==5){
 
																		seis6=6;
 
																		g.drawLine(387,105,387,267);
																		System.out.println("Perdiste!!! =)");
																		}
 
																if(a8==8){
 
																		seis6=6;
 
																		g.drawLine(387,105,387,267);
																		System.out.println("Perdiste!!! =)");
																		}
 
																if (a6==6){
 
																		cinco5=5;
 
																		g.drawLine(175,75,425,300);
																		System.out.println("Perdiste!!! =)");
																			}
																			}
																			}
 
												if (a8 == 8){
 
														cinco5=5;
 
 
															if (a2 ==2){
 
																	nove=9;
 
																	g.drawLine(175,75,425,300);
																	System.out.println("PERDISTE");
																	}
 
															if (a3 ==3){
 
																	nove=9;
 
																	g.drawLine(175,75,425,300);
																	System.out.println("PERDISTE");
																	}
 
															if (a4 ==4){
 
																	nove=9;
 
																	g.drawLine(175,75,425,300);
																	System.out.println("PERDISTE");
																	}
 
															if (a6 ==6){
 
																	nove=9;
 
																	g.drawLine(175,75,425,300);
																	System.out.println("PERDISTE");
																	}
 
															if (a7 ==7){
 
																	nove=9;
 
																	g.drawLine(175,75,425,300);
																	System.out.println("PERDISTE");
																	}
 
															if (a9 ==9){
 
																	sete=7;
 
 
 
																	if (a2 == 2){
 
																			quatro=4;
 
																			g.drawLine(212,75,212,300);
																			System.out.println("PERDISTE");
																			}
 
																	if (a3 ==3){
 
																			quatro=4;
 
																			g.drawLine(212,75,212,300);
																			System.out.println("PERDISTE");
																			}
 
																	if (a4 ==4){
 
																			três=3;
 
																			g.drawLine(425,75,175,300);
																			System.out.println("PERDISTE");
																			}
 
																	if (a6 == 6){
 
																			três=3;
 
																			g.drawLine(425,75,175,300);
																			System.out.println("PERDISTE");
																			}
																			}
																			}
 
													if (a9 == 9){
 
															três=3;
 
 
															if (a4 ==4){
 
																	dois=2;
 
																	g.drawLine(175,105,425,105);
																	System.out.println("PERDISTE");
																	}
 
															if (a5 ==5){
 
																	dois=2;
 
																	g.drawLine(175,105,425,105);
																	System.out.println("PERDISTE");
																	}
 
															if (a6 ==6){
 
																	dois=2;
 
																	g.drawLine(175,105,425,105);
																	System.out.println("PERDISTE");
																	}
 
															if (a7 ==7){
 
																	dois=2;
 
																	g.drawLine(175,105,425,105);
																	System.out.println("PERDISTE");
																	}
 
															if (a8 ==8){
 
																	dois=2;
 
																	g.drawLine(175,105,425,105);
																	System.out.println("PERDISTE");
																	}
 
															if (a2 ==2){
 
																	sete=7;
 
 
 
																	if (a5 == 5){
 
																			quatro=4;
 
																			g.drawLine(212,75,212,300);
																			System.out.println("PERDISTE");
																			}
 
																	if (a6 ==6){
 
																			oito=8;
 
																			g.drawLine(212,75,212,300);
																			System.out.println("PERDISTE");
																			}
 
																	if (a8 ==8){
 
																			oito=8;
 
																			g.drawLine(212,75,212,300);
																			System.out.println("PERDISTE");
																			}
 
																	if (a4 == 4){
 
																			cinco5=5;
 
																			g.drawLine(425,75,175,300);
																			System.out.println("PERDISTE");
																			}
																			}
																			}
 
 
}
}