SP_RAT_AREA

 RAT_AREA() Limits the mouse to a rectangular area of the screen

 Returns  None

 Syntax  RAT_AREA(nTop,nLeft,nBottom,nRight)

 Description

 Limits the mouse to a rectangular area of the screen
 determined by <nTop,nLeft,nBottom,nRight>. Mouse cannot move
 outside of these boundaries.

 Examples

  RAT_AREA(10,10,20,20) // limits the mouse to 10,10,20,20 area

 Notes:

 Be sure to set the mouse area back to fullscreen when
 you're done.

 Source: S_MOUSE.ASM