使EasyUI的window、panel、dialog 不被拖出页面

function easyuiPanelOnMove(left, top) {
  var l = left;
  var t = top;
  if (l < 1) {
    l = 1;
  }
  if (t < 1) {
   t = 1;
  }
  var width = parseInt($(this).parent().css('width')) + 14;
  var height = parseInt($(this).parent().css('height')) + 14;
  var right = l + width;
  var buttom = t + height;
  var browserWidth = $(window).width();
  var browserHeight = $(window).height();
  if (right > browserWidth) {
    l = browserWidth - width;
  }
  if (buttom > browserHeight) {
    t = browserHeight - height;
  }
  $(this).parent().css({
    left: l,
    top: t
  });
  };
$.fn.dialog.defaults.onMove = easyuiPanelOnMove;
$.fn.window.defaults.onMove = easyuiPanelOnMove;
$.fn.panel.defaults.onMove = easyuiPanelOnMove;