Okay, i know EXACTLY how you feel. If you feel like you have any chance at all, TAKE IT. By that i mean, if you think she likes youfrom what little bit you all have talked, than take it a step further. Say, "Hey, can I pull you aside for a sec and talk to you?" If she says yes, great. If she'd prefere to talk around her friends, even better because you get to practice talking in front of a group. Either way, you need to tell her you think she seems kool(or slide in a different wprd depending on you age) and ask if she wants to hang out some time like at the movies or whatever. Ask for a phone number so you guys can talk about it further(If you think you'll get that far, have a pen just in case). Remember, think about what you are saying, but dont think too long or you'll look like an idiot. Oh ya, almost forgot, DO SOMETHING! Don't let her slip by. A girl not interested is 1 out of a million. There's plenty more so don't sweat it.
Good Luck,
00Spartan00