Please help me do the bridge!!

Slimmasaurus

I've gone my whole life wishing I could do it.
It's kind of a basic stretch on my cheer team, and I'm like the ONLY one who can't do it. Please help me! Tips, exercises to strengthen the muscles needed, technique... anything would be great!

I don't know how to post pictures but just in case, I mean this: http://globetrekking.files.wordpress.com/2010/06/311.jpg