Description: Clear a window area in the graphics screen
Mapped Command: CLEAR GRAPHICS WINDOW
FUNCTION __ClearGWindow(Pos1_a,Pos1_b,Pos2_a,Pos2_b,bevel)
   if bevel
      clrwin(__XdGE(Pos1_b-.325),__YdGE(Pos2_a+.15),__XdGE(Pos2_b+.325),__YdGE(Pos1_a-.15))
   else
      clrwin(__XdGE(Pos1_b),__YdGE(Pos2_a),__XdGE(Pos2_b),__YdGE(Pos1_a))
   endif                                         // if bevel
RETURN(Void)