Can anyone help me and tell me which movie is this?!

Years ago, I've seen this movie!.!. its goes sumthing like this guy has one night stand in the elevator with a girl, he couldnt see the girl (due to power cut off) and then he goes looking for this mysterious girl!.!. and at the end!. he stands outside the girls' dorm and says sweet things to which all the girls in the dorm open their windows n says "I am the girl", but there was just one girl whose windows were closed and he found her!.

I don't remember any of the actors nor name!.!.!.

Can anyone please help out!?Www@Enter-QA@Com

---

---