What to do with "Hard to get"?

I've known this girl 1 year. We went out 2 times and then she began inviting me to her desk. We would almost kiss and then she'd pull away(sometimes getting upset), but then she'd do the same thing the next day. I backed off a little because of this. The next day she stops at my desk and gives me this suggestive look and then walks away. I sent an email to try and gauge what she was feeling and then she changed completely. She'd talk to me but wouldn't look at me. I thought she lost interest so I left her alone, but then she started initiating conversation again. I figure she play hard to get and go along for 2 days, but got frustrated. I decided to really push things and get close to her. It threw her for a loop and she left the room. After she came back she began talking to me again like she used to. I figured that the game was over, and she hinted that the next day would be special. The next day she still play hard to get and even more flirting w/other guys. Help!