text: /**
   * loading mask support for overlay
   * @author: 承玉<yiminghe@gmail.com>
   */
  KISSY.add("uibase-loading", function(S) {
      S.namespace("UIBase");
      function Loading() {
          //S.log("LoadingExt init");
      }
  
      Loading.prototype = {
          loading:function() {
              var self = this;
              if (!self._loadingExtEl) {
                  self._loadingExtEl = new S.Node("<div " +
                      "class='ks-ext-loading'" +
                      " style='position: absolute;" +
                      "border: none;" +
                      "width: 100%;" +
                      "top: 0;" +
                      "left: 0;" +
                      "z-index: 99999;" +
                      "height:100%;" +
                      "*height: expression(this.parentNode.offsetHeight);" + "'>")
                      .appendTo(self.get("el"));
              }
              self._loadingExtEl.show();
          },
  
          unloading:function() {
              var lel = this._loadingExtEl;
              lel && lel.hide();
          }
      };
  
      S.UIBase.Loading = Loading;
  
  },{
      host:"uibase"
  });
  