Since page content can only be changed using Javascript, you should have the default page content show the error message indicating that Javascript is required. For example:
HTML Code:
<div id="jscheck">
<p>This function requires JavaScript. You're browser does not support the Javascript functions
used to implement this function, or JavaScript is not enabled. Please enable JavaScript on
your browser and refresh the page.</p>
</div>
And then create a script that will replace the error message if JavaScript is enabled on the visitor's browser.
Code:
<script>
if (document.getElementById) {
formarea = document.getElementById("jscheck");
formarea.innerHTML = '<p>You have JavaScript enabled! Yay!</p>';
}
</script>