If you have a multiple monitor setup and compile the following code. On x86, the child window opens in the middle of the main window wherever it is placed on either desktop. If you compile it on the x64 compiler, it will open the child window on the center of the main window on the first desktop but if you move it to the second, it will open the child window on the edge of the first desktop.
Code:
Enumeration
#MAIN
#CHILD
#BUTTON
EndEnumeration
OpenWindow(#MAIN, #PB_Ignore, #PB_Ignore, 500, 500, "Parent", #PB_Window_SystemMenu | #PB_Window_ScreenCentered )
ButtonGadget(#BUTTON,100,100,300,300,"Press Me!")
exit=#False
Repeat
event=WaitWindowEvent(20)
If EventGadget()=#BUTTON
OpenWindow(#CHILD, #PB_Ignore, #PB_Ignore, 100, 100, "Child", #PB_Window_SystemMenu | #PB_Window_WindowCentered , WindowID(#MAIN))
EndIf
If EventWindow()=main
If event=#PB_Event_CloseWindow
exit=#True
EndIf
EndIf
Until exit