Problem with GLUI windows

Please, help me!

I have an application with a main window:

main_window = glutCreateWindow( “Representación de Quemaduras” );

And some glui windows for the user to input some values, for example:

glui9 = GLUI_Master.create_glui(“Nuevo modelo”, 0, 325,140);

The problem is that, when I click on the X button of the GLUI window it closes, but the main window closes too!!!How can I do to avoid main window closing?

Hope you help me.
Thank you.