title: can't get an asp:RegularExpressionValidator to work
body: <p>I'm having an issue getting a regex field validator to work for an asp page i'm trying to update.</p>
  
  <p>Here is the asp:Panel stripped down to the important bits:</p>
  
  <pre><code>&lt;asp:Panel ID="pnlEmailAddressCollection" runat="server"&gt;
      &lt;div id="POMInput-wrapper"&gt;
          &lt;div class="POMInput-FieldText"&gt;
              &lt;span class="POMInput-wrapper-text"&gt;Name:&lt;/span&gt;
  
              &lt;br /&gt;
              &lt;span class="POMInput-wrapper-text"&gt;Email Address:&lt;/span&gt;
  
              &lt;br /&gt;
          &lt;/div&gt;
          &lt;div class="POMInput-FieldEntry"&gt;
              &lt;asp:TextBox ID="txtEmailAddress" name="emailAddress" runat="server" CssClass="textInput"&gt;&lt;/asp:TextBox&gt;
              &lt;asp:TextBox ID="txtUserName" runat="server" name="firstName" CssClass="textInput"&gt;&lt;/asp:TextBox&gt;
          &lt;/div&gt;
  
          &lt;asp:RequiredFieldValidator ID="rfvNameValidator"  runat="server" 
              ErrorMessage="Please enter your name"
              ControlToValidate="txtUserName" 
              Display="None" /&gt;
  
          &lt;asp:RequiredFieldValidator ID="RequiredFieldValidator1" runat="server" 
              ErrorMessage="Please enter your email address"
              ControlToValidate="txtEmailAddress" 
              Display="None" /&gt;
  
          &lt;asp:RegularExpressionValidator ID="rfvEmailValidator2" runat="server" 
              ErrorMessage="Please enter a valid email address" 
              ControlToValidate="txtEmailAddress"
              Display="None"
              ValidationExpression="^[A-Za-z0-9._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,4}$" /&gt;
  
          &lt;asp:ValidationSummary ID="ValidationSummary1" runat="server"
              ShowMessageBox="true" 
              ShowSummary="false"
              EnableClientScript="true" /&gt;                        
      &lt;/div&gt;
  &lt;/asp:Panel&gt;
  </code></pre>
  
  <p>It is currently failing on any email i put in. The asp:RequiredFieldValidator's work as expected.</p>
  
  <p>I tested the regular expression in a test project and the regex seems good (returns true on valid emails, false on invalid ones). Did I set up the asp:RegularExpressionValidator incorrectly?</p>