How can I trigger submit button thruough the Enter key in both Netscape and Internet Explorer?

This script works both in IE and NS because of the evt.which (IE) and evt.keyCode (NS) enjoy:

<SCRIPT LANGUAGE="JavaScript1.3">
//Enter-listener
if (document.layers)
  document.captureEvents(Event.KEYDOWN);
  document.onkeydown =
    function (evt) { 
      var keyCode = evt ? (evt.which ? evt.which : evt.keyCode) : event.keyCode;
      if (keyCode == 13)   //13 = the code for pressing ENTER
 
      {
         document.form.submit();
      }
    }
</SCRIPT>