Screen.AvailableTop
From Xojo Documentation
Read-Only Property (As Integer )
The number of usable pixels from the top edge of the specified screen. It takes into account the height of the menubar and taskbar, if present, on the specified screen.
Notes
Use the Screen method to call AvailableTop. For example, Screen(0).AvailableTop returns the available top number of pixels of the main screen.