style.display = 'none' makes the error msg not display again

I have a clear button and onClientClick, I call a javascript function. This is what's happening

1. I click the submit button and an error msg is displayed because the textbox is empty
2. I click Clear and the Javascript is called and the error msg is cleared
3. So far so good
5. I click Submit again, and the textbox is empty but this time, the error msg is not displayed.

I think it's because of style.display = 'none' that wont allow the error msg to be displayed again.

Anything else i can use besides style.display ='none'?

<script type="text/javascript">
      function clrCtrl() {

          document.getElementById("<%= ccNumber.ClientID %>").value = "";
          document.getElementById("<%= RequiredFieldValidator4.ClientID %>").style.display = 'none';
         
      }

   </script>