If a panel does not load remote content successfully, the 'onLoadError' event fires. Please bind the 'onLoad' and 'onLoadError' events on your special panels.
<div class="easyui-tabs">
<div title="tab1" data-options="
onLoad: function(){
//...
},
onLoadError: function(){
//...
}
"></div>
<div title="tab2"></div>
</div>