can't close windows in runtime application

[iNcR3d1bl3]

Hi!

I'm new to filemaker and so far I have created a runtime application with several functions including buttons that open new windows. However, all the windows have the "X" greyed out so I can't seem to close the windows other than creating a custom button to close the window. Is there a way to fix that problem? What am I doing wrong?

Thanks for any help.