First of all, if you know you pissed her off last time she saw you you should have gone in like you didn't know her. Built up a conversation and be the cool guy. If she recognized you then be like "I can't believe it's you, you know I had the biggest crush on you back in high school but you always pushed me away so it's my turn bitch... (walk away then turn around) I decided I would give you a chance to make it up to me, let's dance." Just say it all with a smile and play it cool. It's 2013, she wont care about something that small from 12 years ago, I piss girls off and get with them a week later, just have a smiley mentality. Peace bro