Am I missing something? Why don't you just call the Close() method on the form?
I'm completely new in GUI for .NET, so I'm trying to learn...
First thing is, I didn't find out how to get the handle of the form with the container into the ABL Window (.w). Then when the user clicks in the button in the ABL Window (.w), the ABL Window gets closed (apply "window-close" to C-Win). But where do I need to close the form with the window-container. I was hoping that there was a trigger of the window container when the embedded window is closed. I need some sort of mechanism that the two ways are possible. So closing the tab with the little cross (that's ok now) and the other way around, closing in the embedded window.