>Even though I'm not VFP I want to know if there is a windows API function that will let you see which mouse button was click ANYWHERE on the screen.

Dubious. Windows sends messages directory to individual windows (including the desktop) concerning mouse events via their callback functions. There are a number of mouse associated messages such as: WM_MBUTTONDOWN, WM_MBUTTONUP and the message includes a parameter specifying the particular co-ordinates. PeekMessage() might help but only for the current thread.