Well I've had the same problem buddy and mho is that if you really like a friend (have fallen in love with her) you should take your chances and see how she feels about you. I can't be friends with a girl I like, if I know there will never be anything else but friendship. If she falls in love with someone else and starts dating another guy, are you gonna pretend that you're happy for her? Hell I won't! Just imagine what it will feel like if she comes to you and tells you how wonderful this guy is. I'll be gnawing my teeth. As I said in the beginning this is only my opinion on the matter, but I suppose you have the following options:

A. Tell the girl how you feel and who knows, she might feel the same way. If she doesn't feel the same way, talk to her about the mixed messages she's sending out and if you feel that she isn't being honest, give her the finger and show her the door.

B. Stay friends with her and hope you meet someone else that will make the feelings you have for her, go away.

C. Stay friends with the girl and fall asleep every night thinking about her.

I'd say start with option A. If she doesn't feel the same way about you, you can try option B.