title: ToolkitScriptManager: how are some script files located?
body: <p>I have a ASP.NET 4.5 Webform project using the standard Internet template.  Included in Site.Master is:</p>
  
  <pre><code>&lt;ajaxToolkit:ToolkitScriptManager runat="server"&gt;
      &lt;Scripts&gt;
          &lt;%--Framework Scripts--%&gt;
          &lt;asp:ScriptReference Name="jquery" /&gt;   &lt;!-- ??? --&gt;
          &lt;asp:ScriptReference Name="jquery.ui.combined" /&gt;  &lt;!-- ?? --&gt;
          &lt;asp:ScriptReference Name="WebForms.js" Path="~/Scripts/WebForms/WebForms.js" /&gt;
          ...
  </code></pre>
  
  <p>The two jquery lines above apparently cause the following to be generated in the html document:</p>
  
  <pre><code>&lt;script src="Scripts/jquery-1.7.1.js" type="text/javascript"&gt;&lt;/script&gt;
  &lt;script src="Scripts/jquery-ui-1.8.20.js" type="text/javascript"&gt;&lt;/script&gt;
  </code></pre>
  
  <p>May I know how/where does ASP.NET know the link to these two files?</p>
  
  <p>--</p>
  
  <p>July 30 updates:</p>
  
  <p>I found <a href="http://blogs.msdn.com/b/webdev/archive/2012/09/21/asp-net-4-5-scriptmanager-improvements-in-webforms.aspx" rel="nofollow">this</a> which describes how the jQuery scripts are registered in a 4.5 Web Form application.  The code sample shows exactly how the selected version of the jQuery scripts are linked in.  It says it is executed in the <code>PreApplicationStart</code> method which runs before Application_Start.  I searched my whole project for "PreApplicationStart" but could not find anything.  Anyone knows where this is located?</p>