title: Email validation expression
body: <p>After writing this, also while entering email it is showing an error message and it is working fine. I don't know whats going on. Any one please explain once. Thanks in advance</p>
  
  <pre><code>&lt;asp:RequiredFieldValidator ID="Txt5" runat="server" ControlToValidate="TextBox5" ValidationGroup="abc" ErrorMessage="*"&gt;&lt;/asp:RequiredFieldValidator&gt;
          &lt;asp:RegularExpressionValidator ID="Txt05" runat="server" ControlToValidate = "TextBox5" Display ="Dynamic" ValidationExpression="^\w+([-+.']\w+)*@domain.com$" ErrorMessage="Please enter valid email address.."&gt;&lt;/asp:RegularExpressionValidator&gt;
  </code></pre>