Hello!
What about this?
http://dev.sencha.com/deploy/dev/doc...&member=getKey
It should work under all browsers which are officially supported.
Within an event handler you could use just e.getKey().
Example
<%@ Page Language="C#" %>
<%@ Register Assembly="Ext.Net" Namespace="Ext.Net" TagPrefix="ext" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title>Ext.Net Example</title>
</head>
<body>
<form runat="server">
<ext:ResourceManager runat="server" />
<ext:TextField runat="server" EnableKeyEvents="true">
<Listeners>
<KeyUp Handler="alert(e.getKey())"/>
</Listeners>
</ext:TextField>
</form>
</body>
</html>