I have a problem using the AJAX toolkikt TextboxWatermarkExtender.
It does not show up on my page. I have set up the code as follows:

                    <asp:TextBox ID="name" runat="server"></asp:TextBox>
                    <asp:TextBoxWatermarkExtender ID="nameField" runat="server" WatermarkText="Section name" TargetControlID="name">
                    <asp:RequiredFieldValidator ID="nameVal" runat="server" ErrorMessage="Please give in a section name" ControlToValidate="name" ></asp:RequiredFieldValidator>
                    <asp:ValidatorCalloutExtender ID="nameValExtender" runat="server" TargetControlID="nameVal" ></asp:ValidatorCalloutExtender>

This is all inside an updatePanel. I have checked the source code of the html page that is generated by that code, and i saw that the id of the contentPlaceHolder is put in front of the id of the textboxes, but when i try to add that in code, it gives me an error.
Any help is much appreciated

>but when i try to add that in code, it gives me an error.

Post error (Exception) description and markup (.aspx) here.

ContentPlaceHolder / TextBoxWatermarkExtender is working fine.
You need add ToolkitScriptManager on the top script.
If you got already ScriptManager You need take out from your sript.