Thread: Problem with CardLayout?

What is it supposed to do when there is bad input?

The posted code does not compile without compiler errors.

The code is poorly formatted. Many lines are not indented inside of {}s that should be. That makes the code hard to read and understand,

You need to read the API doc and tutorial about how to use CardLayout.
The code does not tell the layout the names of the components.
http://docs.oracle.com/javase/tutori...yout/card.html

I know there is no errors

That's wrong. There are missing class definitions for the posted code.

import java.awt.*;
import javax.swing.*;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
 
 
public class Gu8il {
    public static void main(String[] args) {
 
    	JFrame f1 = new JFrame("Keith");
		Container cp = f1.getContentPane();
		cp.setLayout(new FlowLayout());
 
		final CardLayout cards = new CardLayout();
 
		final JPanel cardPanel = new JPanel();
		cardPanel.setLayout(cards);
 
 
 
		//First card
		final JPanel firstCard = new JPanel();
        final JTextField tf1=new JTextField("pass",10);      //<<<<<<<<<<< preload for testing
        final JTextField tf2=new JTextField("pass", 10);
        JLabel lab10=new JLabel("Username");
        JLabel lab11=new JLabel("Password");
        final String user = "pass";
        final String passwd = "pass";
 
        JButton switchButton = new JButton("Switch Cards");
 
		  String myText1 = tf1.getText();
		  String myText2 = tf2.getText();
 
        switchButton.addActionListener(new ActionListener() {
		public void actionPerformed(ActionEvent arg0) {
 
		  String myText1 = tf1.getText();
		  String myText2 = tf2.getText();
      System.out.println("mY1="+myText1 + ", mT2="+myText2);   //<<<<<<<<<<<<<<<
		if (myText1.equals(user) && (myText2.equals(passwd)))
			cards.next(cardPanel);
		else  {
         System.out.println("show fifthCard");     //<<<<<<<<<<<<<<<<<
         cards.show(cardPanel, "fifthCard");
      }
		}
		});
 
        firstCard.add(lab10); firstCard.add(tf1);
        firstCard.add(lab11); firstCard.add(tf2);
        firstCard.add(switchButton);
		//end of first card
 
 
 
		//Second card
		final JPanel secondCard = new JPanel();
        final JTextField jTextField1 = new JTextField(20);
		final JTextField jTextField2 = new JTextField(20);
		JLabel myFahrenheit = new JLabel("Enter Fahrenheit");
		JButton myButton = new JButton("Convert");
		ActionListener a1 = new ActionListener() {
		public void actionPerformed(ActionEvent e) {
		Double Fahrenheit = Double.parseDouble(jTextField1.getText());
		Double myCelius = (5.0/9.0)*(Fahrenheit - 32);
		jTextField2.setText(Double.toString(myCelius)+ " degrees celsius");
		}};                                  //????????????????<<<<<<<<<<<<
		myButton.addActionListener(a1);
		secondCard.add(myFahrenheit);
		secondCard.add(jTextField1);
		secondCard.add(jTextField2);
		secondCard.add(myButton);
 
        JButton secondButton = new JButton("Next");
        secondButton.addActionListener(new ActionListener() {
		public void actionPerformed(ActionEvent arg0) {
			cards.next(cardPanel);
		}
		});
		secondCard.add(secondButton);
        //end of second card
 
 
 
		//Third card
		final JPanel thirdCard = new JPanel();
		final JTextField jTextField3 = new JTextField(10);
		final JComboBox cars = new JComboBox();
		 cars.addItem("Honda");
		 cars.addItem("Ford");
 		 cars.addItem("Audi");
 		 cars.addItem("BMW");
 
 		 JButton addbutton = new JButton("Add to List");
 
		ActionListener a3 = new ActionListener() {
         public void actionPerformed(ActionEvent e) {
         	    String myText = jTextField3.getText();
            cars.addItem(myText);
		}};
 
		addbutton.addActionListener(a3);
 
		JButton minusbutton = new JButton("Remove from List");
 
		ActionListener a4 = new ActionListener() {
         public void actionPerformed(ActionEvent e) {
            cars.removeItem(cars.getSelectedItem());
		}};
 
		minusbutton.addActionListener(a4);
 
		thirdCard.add(jTextField3);
		thirdCard.add(cars);
		thirdCard.add(addbutton);
		thirdCard.add(minusbutton);
 
		JButton thirdButton = new JButton("Next");
        thirdButton.addActionListener(new ActionListener() {
		public void actionPerformed(ActionEvent arg0) {
			cards.next(cardPanel);
		}
		});
		thirdCard.add(thirdButton);
		//end of third card
 
 
 
		//Fourth card
		final JPanel fourthCard = new JPanel();
		JButton LL=new JButton("Launch Text Compare");
		JButton LTC=new JButton("Launch Tempeture Converter");
		JButton LARC=new JButton("Launch Add/Remove from ComboBox");
 
		ActionListener a5 = new ActionListener() {
		public void actionPerformed(ActionEvent e) {
//		checkText A1 =new checkText();                    //??????????????????
		}
		};
		ActionListener a6 = new ActionListener() {
		public void actionPerformed(ActionEvent e) {
//		tempConvert A2 =new tempConvert();               //?????????????????
		}
		};
		ActionListener a7 = new ActionListener() {
		public void actionPerformed(ActionEvent e) {
//		AddRemoveItemFromCombo A3 =new AddRemoveItemFromCombo();    //??????????????????
		}
		};
 
		LL.addActionListener(a5);
		LTC.addActionListener(a6);
		LARC.addActionListener(a7);
		fourthCard.add(LL);
		fourthCard.add(LTC);
		fourthCard.add(LARC);
		//end of fourth card
 
 
 
		//Fifth card
		final JPanel fifthCard = new JPanel();
		JLabel fifthLabel=new JLabel("You entered the incorrect username or password");
		fifthCard.add(fifthLabel);
 
		JButton fifthButton = new JButton("Next");
        fifthButton.addActionListener(new ActionListener() {
		public void actionPerformed(ActionEvent arg0) {
			cards.show(cardPanel, "firstCard");
		}
		});
		fifthCard.add(fifthButton);
		//end of fifth card
 
 
		cardPanel.add(firstCard, "firstCard");    //<<<<<<<<<<<   Need name of card<<<<<<<<<<<
		cardPanel.add(secondCard, "");
		cardPanel.add(thirdCard, "");
		cardPanel.add(fourthCard, "");
		cardPanel.add(fifthCard, "fifthCard");
		cp.add(cardPanel);
 
		f1.pack();
		f1.setSize(800,400);
		f1.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		f1.setVisible(true);
    }
}