Ok, here's what you gotta do. Forget what everyone else said! You need to get one of those online detectives and get her address, go there at 2 AM and wait until morning. When she walks out of her house, follow at a short distance, only making yourself visible for small incriments of time,
**IMPORTANT**
Make sure she sees you at least a few times during the day, staring at her, then ducking away - it'll turn her on like crazy! Its like mental kino, and nothing makes a girl go crazy like that mysterious guy following her around all day in a trenchcoat!
That detective probably gave your her number too, right? Well call it! At 3 in the morning of course, make sure she doesn't hear your voice (heavy breathing helps, it really adds to the effect!) then hang up. Wait ten minutes, repeat.
By now the girl is hot with wanting for you, and its time to grab her and drag her into a dark alley and...well i guess you know the rest! Good luck man, hope it all works out!