How should i start chatting with the girl i have a crush on Facebook?

[Mazarine]

well, it depends on the relationship you have, if she is already with someone, admit that you like her too, but understand that she is already with someone else, if she isn't you should become friends first, get to know her and laugh together, if you already have a friend relationship just go for it, the worst that can happen is she says no, but you can still be friends, and if she doesn't feel that way about you then accept that sometimes happens. i also reccomend that you ask her out personally. maybe ask her on Facebook if it would be OK to sit together at lunch or get together for coffee, then drop the bomb. good luck xD