title: ASP.NET Error: Content controls are allowed only in content page that references a master page
body: <p>I received the error in the title as a result of the following page:</p>
  
  <pre><code>&lt;asp:Content ID="Content" ContentPlaceHolderID="ContentPlaceHolder" Runat="Server"&gt;
  &lt;atlas:ScriptManager ID="ScriptManager" runat="server"&gt;
  &lt;/atlas:ScriptManager&gt;
  </code></pre>
  
  <p>In this page I use AJAX controls.</p>