extjs tabpanel 添加、刷新iframe

var addtab = function (id, title, iconCls, url, closable) {
if (!Ext.getCmp(id)) {
var close = true;
if (closable != null) {
close = closable;
}
var content = '<iframe scrolling="auto" frameborder="0" id="iframe_' + id + '"  src="' + url + '" style="width:100%;height:100%;"></iframe>';
var page = tabpage.add({
id: id,
title: title,
iconCls: iconCls,
closable: close,
autoScroll: true,
html: content,
// loader: {
//     url: url,
//     loadMask: true,
//     autoLoad: true,
//     scripts: true,
//     listeners: {
//         exception: function (lo, response, options, e) {
//             page.setHtml(response.responseText);
//         }
//     }
// }
});
}
tabpage.setActiveTab(id);
}

function refreshTab(tab) {
var html = tab.config.html;
var iframe = frames['iframe_' + tab.config.id];
var src = iframe.src;
iframe.src = '';
iframe.src = src;
}