code: function(type, args, obj) {
          var useIframe = args[0];
      
          if (!this.parent) {
              if (Dom.inDocument(this.oDomContainer)) {
                  if (useIframe) {
                      var pos = Dom.getStyle(this.oDomContainer, "position");
                      
                      if (pos == "absolute" || pos == "relative") {
                          
                          if (!Dom.inDocument(this.iframe)) {
                              this.iframe = document.createElement("iframe");
                              this.iframe.src = "javascript:false;";
      
                              Dom.setStyle(this.iframe, "opacity", "0");
      
                              if (YAHOO.env.ua.ie && YAHOO.env.ua.ie <= 6) {
                                  Dom.addClass(this.iframe, this.Style.CSS_FIXED_SIZE);
                              }
      
                              this.oDomContainer.insertBefore(this.iframe, this.oDomContainer.firstChild);
                          }
                      }
                  } else {
                      if (this.iframe) {
                          if (this.iframe.parentNode) {
                              this.iframe.parentNode.removeChild(this.iframe);
                          }
                          this.iframe = null;
                      }
                  }
              }
          }
      }
docs: Default Config listener for the iframe property. If the iframe config property is set to true,
  renders the built-in IFRAME shim if the container is relatively or absolutely positioned.
  
  @method configIframe