In VLF-WIN creating a new window is a relatively expensive operation. Often end-users close windows just make them 'get out of the way' and five seconds later they will often open the same window again, usually with different data content.
A simple solution to this problem is to use the parameter KeepOpen(TRUE) in the avShowWindow method or to change the KeepOpen property in class #VF_SY154 window objects.
With KeepOpen(TRUE), when end-users close a window, it is simply minimized just to get it out of their way. This means that in five seconds time when they want to display it again, it does not have to be created from scratch.
When you set a window to KeepOpen(TRUE), it can only be closed when the end-user:
Or when a program changes it to KeepOpen(FALSE).
You should never set the MAIN window to KeepOpen(TRUE).