how to minimize a dialog which comes from a menu item.

I have create a Gui program. A Main window has a menu. when you
choose a menu item, a dialog comes out. but this dialg can be
maximized,closed, but can’t be minimized. The Main windows can
be maximized,closed,minimized.
I have tried some properties,such as
Flags:Render,Flags:Managed,Flags:Notify , but still can’t minimize
this dialog.

Any advice will be appreciated. 3x

have solved In QNX 6.3 OS Plate