PRO Static_Zoom, dir, x0,x1,y0,y1

  Clear_Screen
  PTo,5,5,'Zoom in '+dir+' direction.'
  Print, ' '

  Read,' Please insert the lowest '+dir+' value: ', low
  Read,' Please insert the highest '+dir+' value: ', high

  IF dir EQ 'X' THEN BEGIN 
    x0 = low < high
    x1 = low > high
    Set_XY, x0, x1
  ENDIF ELSE BEGIN
    y0 = low < high
    y1 = low > high
    Set_XY, !x.range(0), !x.range(1), y0, y1
  ENDELSE

END