Basic Cal

import java.applet.*;
import java.awt.event.*;
import java.awt.*;
public class TextFieldAddition extends Applet implements ActionListener
{
    TextField n1,n2,ans;
    int no1=0;
    int no2=0;
    Button a1,a2,a3,a4,clr;
    public void init()
    {
            Label nl1 = new Label("Number 1: ",Label.RIGHT);
            Label nl2 = new Label("Number 2: ",Label.RIGHT);
            Label nl3 = new Label("Answer: ",Label.RIGHT);
            a1 = new Button("ADD");
            a2 = new Button("SUB");
            a3 = new Button("MUL");
            a4 = new Button("DIV");
            clr = new Button("clear");
            n1 = new TextField("0",10);
            n2 = new TextField("0",10);
            ans = new TextField("0",10);

            add(nl1);
            add(n1);
            add(nl2);
            add(n2);
            add(nl3);
            add(ans);
            add(a1);
            add(a2);
            add(a3);
            add(a4);
            add(clr);
                a1.addActionListener(this);
                a2.addActionListener(this);
                a3.addActionListener(this);
                a4.addActionListener(this);
                clr.addActionListener(this);

    }
    public void actionPerformed(ActionEvent ae)
    {
        if(ae.getActionCommand().equals("ADD"))
        {
            no1 = Integer.parseInt(n1.getText());
            no2 = Integer.parseInt(n2.getText());
            ans.setText(String.valueOf(no1+no2));
        }
        else if(ae.getActionCommand().equals("MUL"))
                {
                    no1 = Integer.parseInt(n1.getText());
                    no2 = Integer.parseInt(n2.getText());
                    ans.setText(String.valueOf(no1*no2));
        }
        else if(ae.getActionCommand().equals("SUB"))
                {
                    no1 = Integer.parseInt(n1.getText());
                    no2 = Integer.parseInt(n2.getText());
                    ans.setText(String.valueOf(no1-no2));
        }
        else if(ae.getActionCommand().equals("DIV"))
                {
                    no1 = Integer.parseInt(n1.getText());
                    no2 = Integer.parseInt(n2.getText());
                    ans.setText(String.valueOf(no1/no2));
        }
        else{
                n1.setText("");
                n2.setText("");
                ans.setText("");
        }

    }

}