I have been using a noscript tag to show a warning when users have JavaScript disabled or are using script blocking plugins like Noscript. The website will not function prop
I don't think using is a good idea. I've heard that it is ineffective when the client is behind a JavaScript-blocking firewall - if the client's browser has JavaScript enabled the tag won't activate, because, as far as the browser's concerned, JavaScript is fully operable within the document...
A better method IMO, is to have all would-be 'noscript' content hidden by JavaScript.
Here's a very basic example:
...
Welcome... here's some content...
And within your StyleSheet:
body.js-enabled #noscript { display: none; }
More info: