code: function addIframe(title, url, id) {
  	tabPanel = centerPanel;
  
  	if (tabPanel.getComponent(id) != null) {
  		var arr = url.split('?');
  		if (arr.length >= 2) {
  			tabPanel.remove(tabPanel.getComponent(id));
  
  			var iframe = Ext.DomHelper.append(document.body, {
  				tag: 'iframe',
  				frameBorder: 0,
  				src: url,
  				width: '100%',
  				height: '100%'
  			});
  
  			var tab = new Ext.Panel({
  				id: id,
  				title: title,
  				titleCollapse: true,
  				iconCls: id,
  				tabTip: title,
  				closable: true,
  				autoScroll: true,
  				border: true,
  				fitToFrame: true,
  				contentEl: iframe
  			});
  
  			tabPanel.add(tab);
  			tabPanel.setActiveTab(tab);
  			return (tab);
  		}
  		tabPanel.setActiveTab(tabPanel.getComponent(id));
  		return;
  	}
  
  	var iframe = Ext.DomHelper.append(document.body, {
  		tag: 'iframe',
  		frameBorder: 0,
  		src: url,
  		width: '100%',
  		height: '100%'
  	});
  
  	var tab = new Ext.Panel({
  		id: id,
  		title: title,
  		titleCollapse: true,
  		iconCls: id,
  		tabTip: title,
  		closable: true,
  		autoScroll: true,
  		border: true,
  		fitToFrame: true,
  		contentEl: iframe
  	});
  	tabPanel.add(tab);
  	tabPanel.setActiveTab(tab);
  	return (tab);
  }
docs: auto addPanel