# File lib\Win32/Console.rb, line 840
    def Cls()
      attr = ATTR_NORMAL
      x, y = Size()
      left, top, right , bottom = Window()
      vx = right  - left
      vy = bottom - top
      FillChar(' ', x*y, 0, 0)
      FillAttr(attr, x*y, 0, 0)
      Cursor(0,0)
      Window(1,0,0,vx,vy)
    end