@Logic Ali: You should use a block-level element rather than a SPAN, since the snippet you posted isn't valid with a Strict DTD. In this case, <p>…</p> seems appropriate.
Isn't it easier just to you the <noscript> tag?
I'm for simplicity. :)
Yes, <noscript> is easier. I just answered your question.
Both methods are bad, though.
What do you use then?
What would you not use it for?
It's far easier to describe what I would (and do) use it for.
It can be to perform client-side form validation, for performance reasons. You mustn't rely on this, but have the main validation server-side, but doing it client-side if supported enhances the usability.