Problem with JavaMail... HELP! :(

Hi,

Please somebody help me. I'm programming a Java Room Booking application where the user is required to give details... with an email address being one of them. I want the send an email to the address given as a receipt.

Anyway, it's not working for some reason and I have no idea why. Any help would be great!
Feel free to suggest anything as I'm desperate.
Thanks

Code :

---

public static void sendMail(String e) 
	{
			final String SMTP_HOST_NAME = "smtp.gmail.com";
			final int SMTP_HOST_PORT = 465;
			final String SMTP_AUTH_USER = "";
			final String SMTP_AUTH_PWD  = "";
 
			Properties props = new Properties();
			props.setProperty("mail.transport.protocol", "smtp");
			props.setProperty("mail.host", "smtp.gmail.com");
			props.setProperty("mail.user", "");
			props.setProperty("mail.password", "");
			System.out.println("One");
 
		try
		{
			Session mailSession = Session.getDefaultInstance(props, null);
		    Transport transport = mailSession.getTransport();
 
		    MimeMessage message = new MimeMessage(mailSession);
		    message.setSubject("Room Booking Confirmation");
		    message.setContent("This is a test", "text/plain");
		    message.addRecipient(Message.RecipientType.TO,
		           new InternetAddress(e));
		    System.out.println("Two");
		    transport.connect(SMTP_HOST_NAME, SMTP_HOST_PORT, SMTP_AUTH_USER, SMTP_AUTH_PWD);
		    transport.sendMessage(message,
		          message.getRecipients(Message.RecipientType.TO));
		    System.out.println("Three");
		    transport.close();
		}
		catch (MessagingException ex)
		{
		    System.out.println(ex);
		}
	}

---

do you get any exceptions at all

Well, I'm getting a nosuchprovider exception invalid protocol null