>Nigel,
>
>I think that the problem is that you're assuming that the top and left coordinates are absolute. They're not, they're relative to the VFP desktop and as such don't take into consideration the VFP title bar, menu bar and any existing tool bars. From what I can gather, SYS(1270) relies on the absolute coordinates, not relative. If, for example, I position the mouse over any part of the form and use MROW() and MCOL() to get the position of the mouse to use with SYS(1270), I get back a reference to the the form. If the form's top and left co-ordinates are at 0, 0, and I use 1, 1 I get a reference to the _SCREEN, since 1, 1 is the top upper left hand corner of the VFP main window.

So SYS(1270, _Screen.Width-160, 5) will actually be looking at the titlebar of the VFP main screen? providing the VFP screen is at the top of the physical screen? So to get the correct coordinates, I'd have to calculate where the top of the VFP client area is on the physical screen. This is purely for the purpose of general understanding now as I've solved my problem by other means.