the browser content does not display

[getianyu2008]

the browser content does not display when i set setUndecorat(true) in Simple sample code file.

Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
Insets screenInsets = Toolkit.getDefaultToolkit().getScreenInsets(getGraphicsConfiguration());
// setUndecorated(true); //problem?
setLocation(0, 0);
setSize(screenSize.width - screenInsets.left - screenInsets.right,
screenSize.height - screenInsets.top - screenInsets.bottom);
getContentPane().add(browerUI_);

getContentPane().setVisible(true);
setVisible(true);


but add a button that works well.