PHP Parse HTML code

Possible Duplicate:
Best methods to parse HTML

How can I parse HTML code held in a PHP variable if it something like:

<h1>T1</h1>Lorem ipsum.<h1>T2</h1>The quick red fox...<h1>T3</h1>... jumps over the lazy brown FROG!

I want to only get the text that's between the headings and I understand that it's not a good idea to use Regular Expressions.