text box and command button

import java.awt.*;
import java.awt.event.*;
class p1 extends Frame implements ActionListener{
TextField tf;
p1(){

tf=new TextField();
tf.setBounds(60,50,170,20);
Button b=new Button("click me");
b.setBounds(100,120,80,30);


b.addActionListener(this);


add(b);add(tf);
setSize(300,300);
setLayout(null);
setVisible(true);
}
public void actionPerformed(ActionEvent e){
tf.setText("Welcome");
}
public static void main(String args[]){
new p1();
}
}