Dialog info (take 2)

I asked a question earlier about passing data between dialog and parent with events.
I have tried to implement that solution which seemed to be fairly straight forward (and im sure was)
the following code works until i try to send data through an event if the data is transferred right away (through the constructer) i have no problem.
Also creating the new instance of the dialog seems a bit strange to have to pass the parent (itself) twice...
I seem to be real close to getting this accomplished, I just need a gentle push (or violent shove (you choose)) in the right direction.

The code is as follows:
(please excuse the non-conventional class/file names .. this was suppose to be a quick test)

/** testGUI is the main Frame that displays dialog info

//testGUI.java
*/

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


public class testGUI extends Frame implements DataChanger  {
    TextArea sentence;
    Button button1;
    TextField field;
        testGUI()  {
                this.setBackground(Color.lightGray);
                this.setLayout(new FlowLayout(FlowLayout.CENTER,10,10));
                field= new TextField(10);
                this.add(field);
                sentence= new TextArea(10,75);
                sentence.setEditable(false);
                this.add(sentence);
                button1=new Button("TRY");
                button1.addActionListener(new B1());
                this.add(button1);
                }

        public String getListData()  {
                return field.getText();
                }

        public void setTextData(String data)  {
                sentence.append("Received from dialog: " + data + "\n");
                }
        class B1 implements ActionListener  {
                public void actionPerformed(ActionEvent e)  {
                        testlog d= new testlog(testGUI.this,testGUI.this);
                        d.show();
                        }
                }

        public static void main(String[] args)  {
                Frame f= new testGUI();
                f.addWindowListener(new WindowAdapter()  {
                        public void windowClosing(WindowEvent e)
                                {System.exit(0);}
                        });
                f.pack();
                f.setVisible(true);
                }
        }

/** testlog is the class that implements the dialog box and
handles the events

//testlog.java
*/


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

public class testlog extends Dialog  {
    Button ok;
    Button cancel;
    TextField text;
    DataChanger dc;

        testlog(Frame parent,DataChanger dc)  {  
                super(parent,"Test",true);
                this.setLayout(new FlowLayout(FlowLayout.CENTER,10,10));
                text= new TextField(10);
                this.add(text);
                ok= new Button("OK");
                ok.addActionListener(new BOK());
                cancel= new Button("CANCEL");
                cancel.addActionListener(new BCAN());
                this.add(ok);
                this.add(cancel);
                text.setText(dc.getListData());
                dc.setTextData("from constructer");    //works
                this.pack();
                }
        class BOK implements ActionListener  {
                public void actionPerformed(ActionEvent e)  {
                        dc.setTextData("from event");    //does not work
                        }
                }
        class BCAN implements ActionListener  {
                public void actionPerformed(ActionEvent e)  {
                        testlog.this.dispose();
                        }
                }
        }
       
/**
DataChanger is the the interface
//DataChanger.java
*/
public interface DataChanger  {
        public String getListData();
        public void setTextData(String data);
        }