I need advice!! i have a big problem!!!?

i got on aim, and this person instant messaged me, they asked if they knew who i was, and i said no...but they know everything about me! including what i look like,the school i go 2, and who i hang out with @ school. I am 17 and i wanna know who this person is. everytime i ask who it is he says u obviously dont remember me, and he says that he likes me. doesnt go to my school, and i really wanna know who it is. Any ideas what i ask him to get a good answer from him??? is there a way to figure out who he is only by knowing his screen name?? i need advice? what do i do? what questions do i ask that he will answer? what would u do???I need advice!! i have a big problem!!!?
Keep in mind you only know what this guy is saying to you. Just because he says he does not go to your school does not mean a thing. For the time being, Keep your awareness level at an all time high. Always be aware of your surroundings and if he writes you anything to derogatory print it out and take to the police. This is a crazy world and trust no one! I have 2 daughters that I was so protective of but you girls deal with some real crazies out there. Bottom line BE CAREFUL!!!!!!!!!!!I need advice!! i have a big problem!!!?
I dont know honey, but, BE CAREFUL!!!!