Java program for square root

Java program for square root:

import java.awt.*;
import java.awt.event.*;
import java.io.*;

class SqRoot extends Frame implements ActionListener
 {
   TextField t1,t2;
   Label l1,l2;
   Button b1,b2;

   SqRoot()
   {
    setVisible(true);
    setTitle("Special Purpose Claculator");
    setSize(400,400);
  
      l1=new Label("Input no.");
      l2=new Label("Output");
    
      t1=new TextField(10);
      t2=new TextField(10);

      b1=new Button("Calculate");
      b2=new Button("Clear");
      b1.addActionListener(this);
      b2.addActionListener(this);

     Panel p1=new Panel( );
     p1.setLayout(new GridLayout(2,2));

     p1.add(l1);
     p1.add(t1);
     p1.add(l2);
     p1.add(t2);





     Panel p2=new Panel( );
     p2.setLayout(new FlowLayout( ));

     p2.add(b1);
     p2.add(b2);

     Panel p3=new Panel();
     p3.setLayout(new GridLayout(2,1));
     p3.add(p1);
     p3.add(p2);
    add(p3);

   }
  public void actionPerformed(ActionEvent ae)
  {
    try
    {
      if(ae.getSource( )==b1)
      {
        int n=Integer.parseInt(t1.getText( ));
        double y;
        y= Math.sqrt(n);
        t2.setText(""+y);
      }
   else
      {
        t1.setText("");
        t2.setText("");
     }
   }
     catch(Exception e)
     {
       System.out.println("Error..."+e);
        dispose( );
      }

  }
   public static void main(String args[])
   {
     SqRoot s=new SqRoot( );
     s.validate( );
   }
}