This is how I coded the problem which doesnot compile & generate errors given below this code file

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

/*<Html>
<Applet
code = Simpletron1.class
height = 250
width = 614>
</Applet>
</Html>*/

public class Simpletron1 extends JApplet implements ActionListener
{
//Constant variables used in the program

final int READ=10,
WRITE = 11,
LOAD =20,
STORE = 21,
ADD = 30,
SUBTRACT = 31,
DIVIDE = 32,
MULTIPLY = 33,
BRANCH = 40,
BRANCHNEG = 41,
BRANCHZER0 = 42,
HALT = 43;

//Other variables of the program

int memory[],
accumulator = 0,
instructionRegister = 0,
instructionCounter = 0,
operationCode = 0,
operand = 0;


//GUI components used in the program

JLabel lMemory,
lDataOrInstruction,
lRegistersAndTheirCurrentValues,
lAccumulator,
lInstructionCounter,
lInstructionRegister,
lOperationCode,
lOperand;

JTextField tMemory,
tDataOrInstruction,
tAccumulator,
tInstructionCounter,
tInstructionRegister,
tOperationCode,
tOperand;
JTextArea startArea;

JButton bDone, bExecuteNextInstruction;

String display = " ";

DecimalFormat twoDigits, fourDigits;


public void init()
{
Container c = getContentPane();
c.setLayout(new FlowLayout());

display = "*** Welcome to Simpletron! ***\n"+
"*** Please enter your program one instruction or data word at a time into the ***\n"+
"*** input text field before which I display the location number with a question ***\n"+
"*** mark (?). Press Done button to stop entering your program ***\n";

twoDigits = new DecimalFormat("00");
fourDigits = new DecimalFormat("0000");

memory = new int[100];

startArea = new JTextArea(6, 60);
startArea.setFont(new Font("Courier", Font.BOLD, 12));
startArea.setText(display);
c.add(startArea);

lMemory = new JLabel("Memory");
c.add(lMemory);
//tMemory = new JTextField(5);
//tMemory.setText(twoDigits.format(instructionCounter)+ " ?");
//c.add(tMemory);

lDataOrInstruction = new JLabel("Instruction/Data");
c.add(lDataOrInstruction);
tDataOrInstruction = new JTextField(10);
tDataOrInstruction.addActionListener(this);
c.add(tDataOrInstruction);

Icon bug1 = new ImageIcon("cdbug2.gif");
bDone = new JButton("Done", bug1);
bDone.addActionListener(this);
c.add(bDone);

Icon bug2 = new ImageIcon("cdbug3.gif");
bExecuteNextInstruction = new JButton("Execute Next Instruction", bug2);
c.add(bExecuteNextInstruction);

Icon bug3 = new ImageIcon("bug1.jpg");
lRegistersAndTheirCurrentValues = new JLabel("Registers And Their Current Values:-- ", bug3, SwingConstants.LEFT);
c.add(lRegistersAndTheirCurrentValues);

lAccumulator = new JLabel("Accumulator");
c.add(lAccumulator);
tAccumulator = new JTextField(5);
tAccumulator.setText("0000");
c.add(tAccumulator);

lInstructionCounter = new JLabel("Instruction Counter");
c.add(lInstructionCounter);
tInstructionCounter = new JTextField(5);
//tInstructionCounter.setText(twoDigits.format(instructionCounter));
c.add(tInstructionCounter);

lInstructionRegister = new JLabel("Instruction Register");
c.add(lInstructionRegister);
tInstructionRegister = new JTextField(5);
//tInstructionRegister.setText("+0000");
c.add(tInstructionRegister);

lOperationCode = new JLabel("Operation Code");
c.add(lOperationCode);
tOperationCode = new JTextField(5);
//tOperationCode.setText(twoDigits.format(operationCode));
c.add(tOperationCode);

lOperand = new JLabel("Operand");
c.add(lOperand);
tOperand = new JTextField(5);
//tOperand.setText(twoDigits.format(operand));
c.add(tOperand);


}
public void actionPerformed(ActionEvent e)
{
if(e.getSource() == tDataOrInstruction)
{
above:
for(instructionCounter = 0; instructionCounter<memory.length; instructionCounter++)
{

tDataOrInstruction.setText(twoDigits.format(Integer.toString(instructionCounter))+" ?"+e.getActionCommand());

//1// To store what the user input into tDataOrInstruction text field in memory after conveting into integer
memory[instructionCounter] = Integer.parseInt(tDataOrInstruction.getText());

//2// Assign these values to instrutionRegister
instructionRegister= memory[instructionCounter];

//3// Display value of tInstructionRegister
tInstructionRegister.setText(fourDigits.format(Integer.toString(instructionRegister)));

//4// Extract the valuse of operationCode from instructionRegister
operationCode = instructionRegister/100;

//5// Display this value in tOperationCode text field
tOperationCode.setText(twoDigits.format(Integer.toString(instructionCounter)));

//6//Extract the value of operand from instructionRegister
operand = instructionRegister%100;

//7// Display this value in tOperand text field
tOperand.setText(twoDigits.format(Integer.toString(operand)));

if(instructionCounter==0)
continue above;

//To display the value of memory location when instructionCounter is 1
tMemory.setText(twoDigits.format(Integer.toString(instructionCounter)+" ?"));

//To display the value if instructionCounter in tInstructionCounter text field
tInstructionCounter.setText(twoDigits.format(Integer.toString(instructionCounter)));

}

}
if(e.getSource() == bDone)
{
display = "\t\t*** Program loading completed. ***\n"+
"\t\t*** Program execution begins. **\n";
startArea.append(display);
Dump dump= new Dump();
//dump.height(200);
//dump.width(500);
//dump.setVisible(true);
}
}
}


[COLOR=orangered] The error generated compailing the file[/COLOR=orangered]


at java.awt.Component.dispatchEvent(Component.java:3476)
at java.awt.KeyboardFocusManager.redispatchEvent(KeyboardFocusManager.java:1713)
at java.awt.DefaultKeyboardFocusManager.dispatchKeyEvent(DefaultKeyboardFocusManager.java:627)
at java.awt.DefaultKeyboardFocusManager.preDispatchKeyEvent(DefaultKeyboardFocusManager.java:831)
at java.awt.DefaultKeyboardFocusManager.typeAheadAssertions(DefaultKeyboardFocusManager.java:741)
at java.awt.DefaultKeyboardFocusManager.dispatchEvent(DefaultKeyboardFocusManager.java:592)
at java.awt.Component.dispatchEventImpl(Component.java:3505)
at java.awt.Container.dispatchEventImpl(Container.java:1627)
at java.awt.Component.dispatchEvent(Component.java:3476)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:456)
at java.awt.EventDispatchThread.pumpOneEventForHierarchy(EventDispatchThread.java:201)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:151)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:145)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:137)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:100)

:confused