XHTML, for those of you who don't already know, is simply an amalgamation of XML and HTML, no surprises there. Chances are that you're well versed in HTML, so don't bother rushing out to by a book on XHTML. There are just a few simple rules that we must now comply with. If we do this successfully, we open up so many exciting opportunities for our document! I mean, think about it, our document will actually become well-formed XML. We could interact with so many applications and scripts and applets and and and... Alright, it's not as exciting as I made it sound, but it's darn handy.

Rule Numero Uno: Well-formedness

This primarily means that all elements are properly closed, as well as nested properly. Let me explain these both clearly, as well as the further aspects of XHTML.

Nesting

Many times in HTML we could get away with overlapping elements.

<p>This is <strong>overlapped (tsk tsk).</p></strong>

That is morally wrong, unethical, just plain bad. It should be:

<p>This is <strong>nested (beautiful).</strong></p>

Don't try to get away with overlapping anymore, it just won't be tolerated. Consider yourself forewarned!

I Need Closure on that Anecdote!

Remember those days when it was getting near quitting time, and you were getting lazy?

<p>You know what I mean<p>Don't you?!<p>Ahh, the lazy coder style...

Give yourself a slap on the wrist! We must shape up, as XML does not permit the omission of closing tags.

<p>Let's try this again.</p><p>Ahh, much better</p>

'But' you challenge, 'how do you plan to handle empty tags like <br>s and <hr>s?' First of all I commend you for asking, and I assure you, the answer is simple. Take a look:

<hr />
<img src=”/images/logo.jpg” /><br />

There, that's it! That simple little slash at the end terminates the element, and our parser is happy.