AutoCompleteExtender 问题高手求助

  <asp:ScriptManager ID="ScriptManager2" runat="server">
        </asp:ScriptManager>
        <asp:TextBox ID="search" runat="server"></asp:TextBox>
        <cc1:AutoCompleteExtender
         TargetControlID="search"
         ServicePath="WebService.asmx"
            ServiceMethod="GetHotSearchByKeywords"
             MinimumPrefixLength="1"
             EnableCaching="true"
             CompletionSetCount="10"
            ID="AutoCompleteExtender1"
             runat="server">
        </cc1:AutoCompleteExtender>

----------------------------页面代码

[WebService(Namespace = " http://tempuri.org/")]
[WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
//若要允许使用 ASP.NET AJAX 从脚本中调用此 Web 服务，请取消对下行的注释。
 [System.Web.Script.Services.ScriptService]
public class WebService : System.Web.Services.WebService {

    public WebService () {

        //如果使用设计的组件，请取消注释以下行
        //InitializeComponent();
    }

    [WebMethod]
    public string[] GetHotSearchByKeywords(string prefixText, int count)
    {
         return new string[]{"3213","321","321321","3213","3213","3213"};
    }

-=------------------webserver 代码

 ````````就是高不懂  提示不出来  高手指点 下哪里出错了