I do probably oversee someting simple but I can’t figure it out: When I start my application on a Mac my Main window appears. When I use this program in Windows a window is made partly around my Main window. How do I get rid of it? I just want the Main Window. Or is it system-dependent an do I have to change that Window around my Main Window to the right size? Secundary windows ( in the Windowspart) do not have a window around them.
Can I change that, and how? It cannot be to hard but I do not know how. Some code might be helpful. 
[quote=181273:@Tom Prins]I do probably oversee someting simple but I can’t figure it out: When I start my application on a Mac my Main window appears. When I use this program in Windows a window is made partly around my Main window. How do I get rid of it? I just want the Main Window. Or is it system-dependent an do I have to change that Window around my Main Window to the right size? Secundary windows ( in the Windowspart) do not have a window around them.
Can I change that, and how? It cannot be to hard but I do not know how. Some code might be helpful. ;-)[/quote]
You are not very clear. Are you referring to the window frame ? Or something else ?
Very stupid I found out after posting my question, thanks anyway It was wrong coding with Fullscreen!