asp.net 2.0 callbace ajax

可以轻松实现ajax功能,后台异步操作,但要实现页面异步刷新,还需要写javascript来更新页面数据,一般用作从后台取数据等处理,不更新页面,以下是代码
页面代码:

<script type ="text/javascript" >
        function serverdel(rtn)
        {
            document .getElementById ("myload").innerHTML ="ok"
            alert(rtn);
        }
    </script>

<a href="#" onclick='javascript:mydel(<%#Eval("seg_id") %>)'>delete</a>

<span id="myload"></span>

string ICallbackEventHandler.GetCallbackResult()
    {
        return "操作成功!";
    }
    void ICallbackEventHandler.RaiseCallbackEvent(string eventArgument)
    {
        System.Threading.Thread.Sleep(500);
        obj.Delsegment(Int32.Parse(eventArgument));
        BindGrid();
    }

    protected void Page_PreRender(object sender, EventArgs e)
    {
        ClientScriptManager cs = Page.ClientScript;
        string func = cs.GetCallbackEventReference(this,"arg","serverdel",null);
        string strback = "function mydel(arg) { "+func+";document .getElementById ('myload').innerHTML ='正在处理'}";
        cs.RegisterClientScriptBlock(this.GetType(),"back",strback,true);
    }