No JS detection plugin is a WordPress plugin that will display a warning message to your visitors if JavaScript has been disabled on their browser or if their web browser does not support JavaScript.
You just install and activate the plugin and it will do the rest for you.
Handy plugin if you have a JavaScript like slider or video plugin or script on your site and you want it to look good just add this plugin to let the visitors know whats going on. or if you are running AdSense or other Advertising scripts on the site.