title: asp:RegularExpressionValidator, make sure there is no comma in a string
body: <p>I've been trying to read about and test various regular expression testers to find my solution but to no avial. I'm using:</p>
  
  <pre><code>&lt;asp:RegularExpressionValidator ID="RegularExpressionValidator1" 
  ErrorMessage='&lt;%# "*"%&gt;' ValidationExpression="," runat="server"
  ControlToValidate="edit_email" Display="Dynamic" 
  EnableClientScript="true"&gt;&lt;/asp:RegularExpressionValidator&gt;
  </code></pre>
  
  <p>All I want to do is find out if there is a comma in the textbox, which this leads me to believe it would do. I tested this on <a href="http://www.regular-expressions.info/javascriptexample.html" rel="nofollow noreferrer">http://www.regular-expressions.info/javascriptexample.html</a>, as I understand that <code>EnableClientScript="true"</code> means I need to have JavaScript compliant RegEx</p>
  
  <p>Any help would be greatly appreciated, here are the other things I've tried:</p>
  
  <ol>
  <li><code>ValidationExpression=".*\,"</code> Which
  only hides the error message when I
  have a string followed by a comma at
  the end: "123,"</li>
  <li><code>ValidationExpression=".*,"</code> Which only hides the error message when I have a string like: "123,"</li>
  <li><code>ValidationExpression=","</code> Which only hides the error message when I have a string like: "," (only one character, and MUST be a comma)</li>
  <li><code>ValidationExpression="[^,]"</code> Which only hides the error message when I have a string like: "1" (only one character, and must NOT be a comma)</li>
  <li><code>ValidationExpression="/,/"</code> Which never hides the error message</li>
  </ol>