New to Java

Good morning,

I have written the following code for an airline reservation system. The applet will assign the user a seat in either economy or first class. When first class is full, it will offer economy seats. This works - but when it is about to assign the last seat in 'economy', the program stops working. The error messages suggest a problem in the method call to selectSeat() in the 'economy' part of the code. I can't see the problem, though, as this code is identical to the code I used for the 'first class' part.

//Airline booking
//Coded by Eoghain on 16/9/07

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class AirlineApplet extends JApplet implements ActionListener {
	JButton printPass;
	JTextArea outputArea;
	String output;
	int seatType, seatNum, choice;
	boolean[] seatArray = {false, false, false, false, false, false, false, false, false, false};
	
	public void init() {
		
		Container container = getContentPane();
		container.setLayout(new FlowLayout());
		
		chooseType();
		
		printPass = new JButton ("Click to print boarding pass");
		printPass.addActionListener(this);
		
		outputArea = new JTextArea(40, 40);
		
		container.add(printPass);
		container.add(outputArea);
		
	}
	
	public void chooseType() {
		seatType = Integer.parseInt(JOptionPane.showInputDialog("Please type 1 first First Class or 2 for Economy"));
		selectSeat(seatType);
	}
		
	
	public void actionPerformed(ActionEvent event) {
		outputArea.append(output);
		
		chooseType();
	}
	
	public void selectSeat(int x) {
		
		//argument selects between first and economy
		
		if (x == 1)
		{
			if (seatArray[0] && seatArray[1] && seatArray[2] && seatArray[3] && seatArray[4])
			{
				choice = Integer.parseInt(JOptionPane.showInputDialog("There are no seats available in First Class. Would you like Economy? 1 for Yes, 2 for No."));
				if (choice == 1)
					selectSeat(2);
				else
					JOptionPane.showMessageDialog(null, "Next flight leaves in 3 hours.");
			}
			else
			{
			//do first stuff and make sure the seat is unoccupied
			seatNum = (int)(Math.random()*5);
				
				if (!seatArray[seatNum])
					seatArray[seatNum] = true;
				else
					selectSeat(x);
						
			output = "Your have seat " + seatNum + " in First Class. \n";
			}
			
		}
		else
		{
			if (seatArray[5] && seatArray[6] && seatArray[7] && seatArray[8] && seatArray[9])
				JOptionPane.showMessageDialog(null, "There are no seats available in Economy. Sorry.");
			else
			{
			//do economy stuff
			seatNum = (5 + (int)(Math.random()*4));
				
				if (!seatArray[seatNum])
					seatArray[seatNum] = true;
				else
					selectSeat(x);
						
			output = "Your have seat " + seatNum + " in Economy. \n";
			}
		}
		
	}
}

Any advice would be greatly appreciated,
-Eoghain