【 tulaoshi.com - Javascript 】
                             
                             先看MSDN Library 2005上的这个例子! 
------ ClientCallback.aspx ------ 
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="ClientCallback.aspx.cs"  Inherits="ClientCallback" % 
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/ xhtml11.dtd" 
<html xmlns="http://www.w3.org/1999/xhtm l"  
    <head id="Head1" runat="server" 
        <titleCallback Test</title 
        <script type="text/javascript" 
        function ReceiveServerData(receivedStr, context) 
        { 
            alert(receivedStr); 
        } 
        </script 
    </head 
        <body 
          <form id="form1" runat="server" 
            <input type="button" value="Callback" onclick="CallServer(’argument’, ’context’)"/<br / 
          </form 
    </body 
</html-------- ClientCallbacp.aspx.cs  ----------- 
// ClientCallback.aspx.cs  
using System; 
using System.Data; 
using System.Configuration; 
using System.Collections; 
using System.Web; 
using System.Web.Security; 
using System.Web.UI; 
using System.Web.UI.WebControls; 
using System.Web.UI.WebControls.WebParts;  
using System.Web.UI.HtmlControls; 
public partial class ClientCallback : System.Web.UI.Page, System.Web.UI.ICallbackEventHandle r 
{ 
    void Page_Load(object sender, EventArgs e) 
    { 
        ClientScriptManager cm = Page.ClientScript; 
        String cbReference = cm.GetCallbackEventReference(this, "arg", "ReceiveServerData", ""); 
        String callbackScript = "function CallServer(arg, context) {" + cbReference + "; }"; 
        cm.RegisterClientScriptBlock(this. GetType(), "CallServer", callbackScript, true); 
    } 
    private string returnStr; 
    //function called by client, executed on server [next]
    public void RaiseCallbackEvent(String eventArgument)     
    { 
        //do something with return argument 
        returnStr = eventArgument.ToUpper(); 
        return; 
    }      
    //function that sends result? 
    public string GetCallbackResult() 
    { 
        return returnStr; 
    } 
} 
客户端用ReceiveServerData接收服务器返回的数据, 
&