Removing JFrame Close Button

try doing this

setUndecorated(true);
getRootPane().setWindowDecorationStyle(JRootPane.PLAIN_DIALOG);

or use Jwindow instead of JFrame

You can use JFrame.setUndecorated(true) and JFrame.getRootPane().setWindowDecorationStyle(some_style_without_close_button), but this will only work if the current windowing system supports disabling native decorations (MS Windows does), and if the current look-and-feel supports window decorations. A quick test (in J2SE 1.4.2) shows that:

Metal LAF -- supports
Motif LAF -- does not support
Windows LAF -- does not support

i got this info from web, please check it once.

try this, this will disable the close button.
JFrame.this.setDefaultCloseOperation(WindowConstants.DO_NOTHING_ON_CLOSE);

What I wanna do is to remove the close button totally..

What is the issue with undecorated? You want the other buttons like minimize to be present?

The issue w/ undecotated is it will also remove the titlebar wherein i just want to remove the close button.