accessing a textfield

[turkmen38]

hi every one
i am new to java and object oriented programming.my problem is that i wanna acces a text field...in a frame i created a text area and a button.i want to populate textarea when the button is clicked..i know it is very simple to you but i have been struggling with this for hours.....below is the source code...
thanx in advance

----------------------
/*
* i am trying to populate a textfield or textarea when a button is clicked...
*/
import java.awt.*;
import java.awt.event. *;
import java.awt.Button ;
public class ForTestPurposes Only extends GUIFrame
implements TextListener,Ac tionListener{
String msg=new String(" ");
int flag =0;
public ForTestPurposes Only(){
super("Buttons And Text components together");
Button button=new Button("Click me!!!!");
button.addActio nListener(this) ;
add(button,Bord erLayout.SOUTH) ;
setSize(100,100 );
setVisible(true );
TextField tf=new TextField();
tf.addTextListe ner(this);
add(tf,BorderLa yout.NORTH);
pack();



}

public void actionPerformed (ActionEvent event){
if (event.getSourc e() instanceof Button){
System.out.prin tln();

if (flag==0){
flag=1;
}
else{
flag=0;

}

}
}




public void textValueChange d(TextEvent event){
TextComponent src=(TextCompon ent)event.getSo urce();
if(flag==1){
src.setText("mu rtaza");
}
else{
src.setText("") ;
}

}







public static void main(String args[]){
new ForTestPurposes Only();
}




}