[G_rose42]

<asp:ScriptManager ID="ScriptManager1" runat="server"  EnablePageMethods="true">
     <Services>
          <asp:ServiceReference Path="../Service/WebService.asmx" />
         </Services>
</asp:ScriptManager>

I used above coding to access functions from WebService.asmx page
i can able to access the function from clientside using javascript but am getting the following error

I got the following Error

Microsoft JScript runtime error: AjaxControlToolkit requires ASP.NET Ajax 4.0 scripts. Ensure the correct version of the scripts are referenced. If you are using an ASP.NET ScriptManager, switch to the ToolkitScriptManager in AjaxControlToolkit.dll.

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Instead of that i used the below coding i didn't get any error but i couldn't able to access the functions from clientside using javascript

<ajax:ToolkitScriptManager ID="ToolkitScriptManager1" runat="server">
        <Services>
            <asp:ServiceReference Path="../Service/WebService.asmx" />           
        </Services>
    </ajax:ToolkitScriptManager>