title: ASP.NET: ValidationSummary doesn't display any contents
body: <p>I'm trying to figure out how the heck the validation summary control of ASP.NET (3.5 I think) works.</p>
  
  <pre><code>&lt;asp:ValidationSummary ID="vldSummary" runat="server" DisplayMode="BulletList" 
    CssClass="error" EnableClientScript="true" /&gt;
  &lt;asp:RequiredFieldValidator ID="vldSubject" ControlToValidate="txtSubject"
    EnableClientScript="false" Text="You must enter a subject." runat="server" /&gt;
  &lt;asp:RequiredFieldValidator ID="vldMessage" ControlToValidate="txtMessage"
    EnableClientScript="false" runat="server" Text="You must enter a message." /&gt;
  </code></pre>
  
  <p>It seems that no matter what I do, the validation summary remains empty (but <em>is</em> rendered) and the errors are only displayed at the position of each respective validator.</p>
  
  <p>What am I doing wrong?</p>