How to detect if JavaScript is disabled?

Question

There was a post this morning asking about how many people disable JavaScript. Then I began to wonder what techniques might be used to determine if the user has it disabled.

Answer 1

Because I always want to give the browser something worthwhile to look at I often use this trick:

First, any portion of a page that needs JavaScript to run properly (including passive HTML elements that get modified through getElementById calls etc.) are designed to be usable as-is with the assumption that there ISN'T javaScript available. (designed as if it wasn't there)

Any elements that would require JavaScript, I place inside a tag something like:

Then at the beginning of my document, I use .onload or document.ready within a loop of getElementsByName('jsOnly') to set the .style.display = ""; turning the JS dependent elements back on. That way, non-JS browsers don't ever have to see the JS dependent portions of the site, and if they have it, it appears immediately when it's ready.

Once you are used to this method, it's fairly easy to hybridize your code to handle both situations, although I am only now experimenting with the noscript tag and expect it will have some additional advantages.