Function:   MouseChar()

               With this function, you will be able to define a
               character to be used as mouse Cursor. the Cursor
               can be any character from the ASCII set, or can
               default to the current character. The color will
               allways be the current's position's complementary
               color attribute.

  Syntax:     MouseChar([<nChar>])

  Arguments:  <nChar> is the character to use as Mouse Cursor,
               if ommitted, the current character on screen with
               other color (Complementary Color) will be used.

  Returns:    Nothing.

  Usage:      * Select chr(4) as Mouse Cursor:
               MouseChar(4)

               * Standard Mouse Cursor:
               MouseChar()

               * Check (.) the mouse, then normal again:
               MouseChar(251)   /* Select . char */
               Delay(1)         /* Just show it a moment */
               MouseChar()      /* Normal again */