Well, you've read all about the code, now what's this validation business? It's very simple. The `official' HTML validator is W3C's own validator, which is located at W3C's Validation Service homepage. Once you are ready to validate your document, go there and scroll down to the box where it says `Validate by URI' and type in the URL of your document.

A note on webspace providers. Below is a list of the most popular free webspace providers and how their pages validate with W3C. Why did I add this feature? Because some webspace providers add their own, sometimes inaccurate, code into your pages [and there's nothing you can do about it, because it's in their Terms of Service]