the samples from the AJAX toolkit have nothing about hoverextender and only one sample about hovermenuextender control. And this sample don't use a webservice.
So here my experience after hard debugging: The important part is the Webmethod signature which needs exactly the parameter name contextKey. I searched hours in google and didn't find an hint about that.
If you use a webservice you need the attribute starting "dynamic..". The result is shown in the control [dynamiccontrolid] which can be the same as [popupcontrol].
<%
@ Page Language="VB" %> <%
@ Register Assembly="AjaxControlToolkit" Namespace="AjaxControlToolkit" TagPrefix="cc1" %> <
script runat="server"> <WebMethod()> _
<ScriptMethod()> _
Public Shared Function Nachladen1(ByVal contextKey As String) As String Return "Hannes Preishuber" End Function </
script> <
html xmlns="http://www.w3.org/1999/xhtml" > <
head runat="server"></head> <
body> <form id="form1" runat="server"> <asp:ScriptManager ID="ScriptManager1" runat="server"> </asp:ScriptManager> <asp:Button ID="Button1" runat="server" Text="Button" /> <cc1:HoverMenuExtender ID="HoverMenuExtender1" runat="server" PopupControlID="Panel1" TargetControlID="Button1" PopupPosition="Left" BehaviorID="hmb1" DynamicControlID=Label1 DynamicServiceMethod="Nachladen1" DynamicContextKey="test"> </cc1:HoverMenuExtender> <asp:Label ID="Label1" runat="server" Text="Label"></asp:Label> <asp:Panel ID="Panel1" runat="server" Height="50px" Width="125px"> show me .....
</asp:Panel> <input id="Button2" type="button" value="button" language="javascript"/></form> </
body> </
html> ajax