plzzzzzzzzz xplain this code 

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

public class Agency extends Frame implements ActionListener
{
	Label l1,l2,l3,l4;
	Button b1;
	TextField t1,t2;
	String s1,s2,s3,s4;


    public static void main(String args[])
   {
	  new Agency().setVisible(true);
   }

    public Agency()
   {
	  super("Gas Agency Package");
	  setSize(1280,800);
	  setBackground(Color.lightGray);
	  setLayout(null);
	 // setLayout(new BorderLayout());


   	  t1=new TextField(20);
   	  t1.setBounds(440,150,200,30);
   	  t1.setBackground(Color.white);
	  t2=new TextField(20);
	  t2.setBounds(440,180,200,30);
      t2.setBackground(Color.white);
	  t2.setEchoChar('*');

 	  l1=new Label("Gas Agency Package");
 	  l1.setBounds(400,30,300,50);

 	  l1.setFont(new Font("TimesRoman",Font.BOLD,25));
 	  l1.setAlignment(Label.CENTER);

 	  l2=new Label("Enter your ID and Passoword");
 	  l2.setFont(new Font("TimesRoman",Font.BOLD,20));
 	  l2.setBounds(270,80,300,50);

 	  l3=new Label("Enter ID");
	   	  l2.setFont(new Font
("TimesRoman",Font.BOLD,20));
 	  l3.setBounds(270,150,120,50);

 	  l4=new Label("Enter Passoword");
	   	  l2.setFont(new Font
("TimesRoman",Font.BOLD,20));
 	  l4.setBounds(270,180,140,50);

       add(l1);
       add(l2);
       add(l3);
       add(t1);
       add(l4);
       add(t2);


 	  b1=new Button("Login");
 	  b1.setBackground(Color.white);
 	  b1.setBounds(400,280,100,70);
 	  b1.addActionListener(this);
 	  add(b1);

   }

    public void actionPerformed(ActionEvent e)
   {

	  if(e.getSource()==b1)
	  {
	     s3="svce";
	     s4="svce";
	     s1=t1.getText();
	     s2=t2.getText();
	     if(s1.equals(s3) && s2.equals(s4))
	     {
			 //System.out.println("password is 
correct");
			 MenuForm m= new MenuForm();
			 m.setVisible(true);
			 //this.dispose();
		 }
		 else
		 {
		 	System.out.println("password  not 
correct");
		}
	     this.dispose();

	  }
   }
}
plzzzzzzzzz xplain this code