I have a page containing much contents. The page may display a custom error message if JavaScript is disabled. The page must not display anything else other than the prompt message. I am posting an image, which is similar to an error prompt I mean. I have an error prompt with some images in my mind..

How can I make this possible?
The general idea is that you would put your message HTML (no reason to use an image, text will work just fine) inside noscript tags like this:
<noscript>You must enable Javascript in order to use this site.</noscript>If you want the noscript HTML to obscure/hide the entire rest of the page, then you will need to make sure whatever it is takes up the entire page and is on top. You could do that with something like this:
Here’s a jsFiddle that shows how the noscript div works. The fiddle doesn’t include the actual
<noscript>tag because the fiddle won’t work without JS, but it shows you how the absolutely positioned div works to block all other content. Scroll down in the HTML area of the fiddle to see the noscript div HTML (which is as I have copied into this post).