function popup(file,height,width)
 {

  if (width == undefined) {
    width = 800;
  }

  if (height == undefined) {
    height = 600;
  }

  var left = 200;

  var popup = window.open(file,"popup","width=" + width + ",height=" + height + ",left=" + left + ",top=20,resizable=no,scrollbars=yes");
  popup.focus();

  return false;
 }