Thread: how to restart in java japplet?

how to restart a game? problem with my code is that when it restarts it double the enemy. so there are 10 enemies and lets say player dies than user restart and now there are 20 enemies and so on.....

in start method i am create 10 enemies and storing in arraylist

public void start()
{
for(int i = 0; i < 10; i++){  
    enemyObject = new Enemy(10*i,10);
    enemyStore.add(enemyObject);    //store in array
}
}

in here i am making enemy move, collision etc and if enemy is dead than i am remooving it from arraylist

public void actionPerformed(ActionEvent e)
{
	for(int i = 0; i < enemyStore.size(); i++){       
		enemyObject = (Enemy)enemyStore.get(i);
			if(!enemyObject.getDead()){               //if enemy is not died
				//make enemy move, collision etc... here
                                ....
			}
			else{           //remove enemy and create another one
				enemyStore.remove(i);
				enemyObject = new Enemy(10*i, 10); //create enemy
				enemyStore.add(enemyObject);                                               //store in array
			}
		}
}

in paint method paint enemy

public class Display extends JPanel
{
    public void paintComponent(Graphics g){	
	super.paintComponent(g);
 
	for(int i = 0; i < enemyStore.size(); i++){      //PAINT ENEMY
		enemyObject = (Enemy)enemyStore.get(i);
		enemyObject.paint(g);
	}
    }
}

in there if player dies than remove all enemies in arraylist and restart

public void mouseClicked(MouseEvent e)
{
if(playerObject.getDead()){
	if(e.getX() > bx && e.getX() < bx + bw)	{
		if(e.getY() > by && e.getY() < by + bh){
			for(int i = 0; i < enemyStore2.size(); i++){
				enemyStore2.remove(i);	
			}		
			start();
		 }
	 }
  }
}

clear the enemyStore when the player dies