When JavaScript is not supported

While most current browsers understand Javascript a lot of the early browsers did not. The current browsers also allow Javascript to be turned off and some people do this. What this means is that not all of the visitors to your page will see the effects of the JavaScript on your page. We need to make sure that these visitors can use our site even without JavaScript.

Other examples in Guidelines (JavaScript tutorial)
Result from the Online TryIt-Editor
chrome 1.0safari 1.0Firefox 1.0ie 3.0opera 4.0