Thread: Hello Everybody

I am a new java programmer i have write a small program but it has some errors please help about this errors.
import java.awt.*;
import javax.swing.*;
import java.awt.event.*;


public class SmallCalcApp implements ActionListener{
JFrame frame;
JLabel firstOperand, secondOperand, answer;
JTextField op1, op2, ans;
JButton plus, mul;


// setting layout
public void initGUI ( ) {
frame = new JFrame();
firstOperand = new JLabel("First Operand");
secondOperand = new JLabel("Second Operand");
answer = new JLabel("Answer");


op1 = new JTextField (15);
op2 = new JTextField (15);
ans = new JTextField (15);
plus = new JButton("+");
plus.setPreferredSize(new Dimension(70,25));

mul = new JButton("*");
mul.setPreferredSize(new Dimension(70,25));

Container cont = frame.getContentPane();
cont.setLayout(new FlowLayout());
cont.add(firstOperand);
cont.add(op1);
cont.add(secondOperand);
cont.add(op2);
cont.add(plus);
cont.add(mul);
cont.add(answer);
cont.add(ans);
plus.addActionListener(this);
mul.addActionListener(this);

frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOS E);
frame.setSize(200, 220);
frame.setVisible(true);
}
//constructor
public SmallCalcApp ( ) {
initGUI();
}
public void actionPerformed(ActionEvent event) {

String oper, result;
int num1, num2, res;

if (event.getSource() == plus) {
oper = op1.getText();
num1 = Integer.parseInt(oper);
oper = op2.getText();
num2 = Integer.parseInt (oper);
res = num1+num2;
result = res+"";
ans.setText(result);
}
else if (event.getSource() == mul) {
oper = op1.getText();
num1 = Integer.parseInt(oper);
oper = op2.getText();
num2 = Integer.parseInt (oper);
res = num1*num2;
result = res+"";
ans.setText(result);
}
public static void main(String args[]) {
SmallCalcApp scApp = new SmallCalcApp();
}
}// end class