How should I ask my crush out?

[915]

I''ll cut to the chase.
We talk a lot on fb and today for the first time around her friends we had a bit of small talk going on, commenting on stuff, she laughed at almost every joke I made.
Anyway, I want to get her alone so I can talk about what I feel for her, whenever I do see her, she's with friends, or she's in a crowded corridor waiting for class.
I think she knows I like her we make eye contact every time we see each other.
Any tips on what I should say, I don't think it'll be a good idea to ask her out infront of people and I don't want to ask her out through fb.
Any ideas?