This is a very common question, and the answer varies upon what you are doing. For instance, what is the site’s intention? Who is your target audience? How far can a user without JavaScript get into your website? These are a few of the questions you should consider before building a website.
Less than 2% of users disable JavaScript or don’t have support. This number is rather low, but does that mean they aren’t worth considering? I’ll try and put that into perspective. Let’s assume you have an eCommerce website and sell $10,000/month of product. If you decide to make users have JavaScript in order to check out, you could be losing $200/month or $2,400/year!
I’m not saying you should always make your website plain and boring with no fade in effects or fancy JavaScript rollovers, because users love things like that. However, crucial parts like registering for the website, checking out, emailing support, and other crucial items should all still work without JavaScript.
Yes, you can still make the contact box fade in when they click “contact,” but make sure there is a fallback for users without JavaScript, so they can still contact you. This is easy to accomplish by making the default link go to the real contact page, but use JavaScript to attach a click event to the link. You can still have fancy JavaScript form validation, but make sure you validate on the server and display appropriate error messages as well.
(Source: Skynet Solutions)
(Source: blog.skynet-solutions.net )
