if(this._xhrDfd &&this._xhrDfd.fired == -1){// we are still in flight, which means we should reset our DeferredHandle// otherwise we will trigger onUnLoad chain of the canceled content,// the canceled content have never gotten onLoad so it shouldn't get onUnloadthis.onUnloadDeferred = null;
}
dijit.layout.ContentPane.prototype.cancel.apply(this, arguments);