how can i send a diferent image to two monitors pluged to one computer with a VGA Splitter

To determine if there are two displays connected to your computer you may use following code:

DECLARE INTEGER GetSystemMetrics IN user32 INTEGER nIndex
lnNumberOfMonitors = GetSystemMetrics(80)

To move your VFP window to the second monitor which is placed on the right side of your main monitor you have to change _screen.Left and _screen.Top properties to be outside of your main display size. E.g. if your main display size is 1280 x 800 the you have to set

_screen.Left = 1300 and _screen.Top can remain unchanged.

You may simply test it from Command window and check the values in form Properties window.

Same is valid for forms displayed As Top-Level forms (Form.ShowWindow property must be set to 2).

One you set the position of the main VFP window it will appear on the same place next time you execute VFP.