Create customized validation function for field
<html> <head> <title>Hello World Window</title> <link rel="stylesheet" type="text/css" href="ext-3.0.0/resources/css/ext-all.css" /> <script type="text/javascript" src="ext-3.0.0/adapter/ext/ext-base.js"></script> <script type="text/javascript" src="ext-3.0.0/ext-all.js"></script> </head> <body> <script type="text/javascript"> Ext.onReady(function() { Ext.QuickTips.init(); var htmlEditor = { xtype : 'htmleditor', fieldLabel : "", anchor : '100% 100%', allowBlank : false, validateValue : function() { var val = this.getRawValue(); return false; } } var f = { xtype : 'form', labelWidth : -20, items : htmlEditor, border : false } new Ext.Window({ title : '', layout : 'fit', height : 300, width : 600, items : f, buttons : [ { text : "Is the html editor valid??", handler : function() { var isValid = Ext.getCmp('ext-comp-1003').form.isValid(); var msg = (isValid) ? 'valid' : 'invalid'; Ext.MessageBox.alert('Title', 'The HTML Editor is ' + msg); } } ] }).show(); }); </script> <div id='div1'>asdf</div> </body> </html>