use [System.Web.Services.WebMethodAttribute(),System.Web.Script.Services.ScriptMethodAttribute()]

Hey there,
I have a function which is is a Web Services as the following:
        [System.Web.Services.WebMethodAttribute(),System.Web.Script.Services.ScriptMethodAttribute()]
        public static string GetDynamicContent(string contextKey)
        {
            //Return a string value base on from the Database
        }

In my GridView I have the following PopupControlExtender:
                                            <asp:PopupControlExtender ID="PopupControlExtender1" runat="server"
   &nbs ...