SetExtMode()
 Set the video mode.
------------------------------------------------------------------------------

 Syntax:

     SetExtMode( [<nRows>], [<nCols>], [<nScanLines>] ) --> lSuccess

 Arguments:

     <nRows> is the number of rows in the desired display mode.  The
     default is MAXROW() + 1.

     <nCols> is the number of columns in the desired display mode.  The
     default is MAXCOL() + 1.

     <nScanLines> is the number of scan lines in the desired display mode.
     The default in 25 line mode is 350.  In 25 line mode, 350 scanlines
     gets rid of the 9th pixel displayed on VGA monitors.

 Returns:

     SETEXTMODE() returns true (.T.) if the mode change was successful;
     otherwise, it returns false (.F.).  SetExtMode() actually returns the
     return value of the SETMODE() which is called internally.  Therefore,
     if the SETMODE() was successful but the scan line change did not,
     the function still returns a (.T.).

 Description:

     SetExtMode() is used to set the video mode including the number
     of scan lines.  If the MOUSE is INSTALLED, it will be re-initialized.

     SetExtMode() actually calls the CA-Clipper SETMODE() function.

     SetExtMode() is an environment function that attempts to change the
     mode of the display hardware to match the number of rows, columns and
     scan lines specified.  The change in screen size is reflected in the
     values returned by MAXROW() and MAXCOL().

 Example:

     The following example switches to a 43-line display mode:

     IF SetExtMode( 43, 80, 350 )

        ? "43-line mode successfully set"

     ELSE

        ? "43-line mode not available"

     ENDIF


 Files:  Library is MOUSE.LIB.