Retrieves the dimensions of the bounding rectangle of the visible area
#include <WinAPIGdi.au3>
_WinAPI_GetClipBox ( $hDC, ByRef $tRECT )
| $hDC | Handle to the device context. |
| $tRECT | $tagRECT structure that is created by this function, and contains the rectangle dimensions, in logical units. |
| Success: | The value that specifies the region's complexity; it can be one of the following values. $COMPLEXREGION $NULLREGION $SIMPLEREGION |
| Failure: | 0. |
Search GetClipBox in MSDN Library.