在APPLET怎么弹出对话框！


import java.awt.*;
import java.awt.event.*;
import java.applet.*;
public class OKDialog extends Dialog {
protected Button okButton;
protected static Frame createdFrame; public OKDialog(Frame parent,String message)
{ super(parent,"告警",false);
GridBagLayout gridbag = new GridBagLayout();
GridBagConstraints  constraints = new GridBagConstraints(); okButton = new Button("OK");
Label messageLabel = new Label(message);
setLayout(gridbag);
constraints.fill = GridBagConstraints.NONE;
constraints.anchor = GridBagConstraints.CENTER;
constraints.ipadx= 20;
constraints.ipady = 20;
constraints.weightx =1.0;
constraints.weighty = 1.0;
constraints.gridwidth = GridBagConstraints.REMAINDER;
constraints.gridheight = GridBagConstraints.RELATIVE;
gridbag.setConstraints(messageLabel,constraints);
add(messageLabel);
constraints.ipadx=0;
constraints.ipady=0;
constraints.weightx=0.0;
constraints.weighty=0.0;
constraints.gridwidth =1;
constraints.gridheight =     GridBagConstraints.REMAINDER;
gridbag.setConstraints(okButton,constraints);
add(okButton); pack();
setBounds(200,150,350,150);
//setResizable(false); } public boolean action(Event evt,Object whichAction)
{
if (evt.target==okButton)
{
dispose();
}
    return true;
} public static void createOKDialog(String dialogString)
{
if (createdFrame==null)
{
createdFrame = new Frame("Dialog");
}
OKDialog okDialog = new OKDialog(createdFrame,dialogString);
DisplayApplet.clip.loop();
createdFrame.resize(okDialog.size().width,okDialog.size().height);
okDialog.show(); }
}
public class Myapplet extends Applet
{
init(){
....
OKDialog.createOKDialog("");
...
}
}