To call a Web Services from Client Script

I've 3 different projects. 1. web services as a web site  2. business layer as project  3. GUI pages as a web site.  

No 2 has web references to the No 1. And .dll of No 2 is in /bin of No 3. I want to make web services call using AJAX from No 1 to No 3. What should be the path for the following code?

<asp:ScriptManager runat="server" ID="scriptManager">
  <Services>
    <asp:ServiceReference path="~/WebServices/SimpleWebService.asmx" />
  </Services>
</asp:ScriptManager>

 

 
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