title: ValidationSummary is not displaying - with RegularExpressionValidator
body: <p>below is the code and when i select a wrong filetype i get instant red "*" but i dont see the validation summary and there is a buton("upload") and when i click on it than i get the validation summary error message.</p>
  
  <p>my question is: why validation summary is not displaying when i select the wrong file type?</p>
  
  <pre><code>&lt;asp:ValidationSummary ForeColor="DarkRed" 
   ID="ValidationSummary1" runat="server" ShowMessageBox="False"
   HeaderText="To save this page, the following required fields must be completed:" ShowSummary="true" /&gt;
  
    &lt;asp:RegularExpressionValidator ID="RegularExpressionValidator2" EnableClientScript="true" runat="server" ControlToValidate="fUpload"
  ValidationExpression="^(([a-zA-Z]:)|(\\{2}\w+)\$?)(\\(\w[\w].*))(.rtf|.RTF|.Rtf|.xls|.XLS|.Xls)$" Text="*"
  ErrorMessage="Invalid file type" SetFocusOnError="true" Display="Dynamic"&gt;/&gt;&lt;/asp:RegularExpressionValidator&gt; 
  </code></pre>