What should I so about this girl!?

[S]

Ok so a few months ago I was on Facebook and a friend of mine changed her Facebook profile pic... And their was this girl in it a fire of hers...I mean wow....
Ok so yesterday I seen her at a disco I mean she was staring but with a gentle look not stern... And I couldn't literally take my eyes off her...
I seen her staring at me even when she was walking off with a guy so I taught nothing of it...'m good friends with her friend and we were sitting at the disco and just chatting a good bit she was leaning on me etc.... I think she likes me)
But she added me later so I don't know is it because she likes me or because her friend does and we were talking (someone taught we were together)...
I swear I heard lighthouse playing in my head..just the words 'I don't Know why but I can't take my eyes off of you'
I don't even know this girl...
I put It in this section because in dating it's just girls moaning about dicky boyfriends loving them one minute and being a tool the next...

[Joe]

Ask her out. The worst thing she can say is no or she already got one

[math]

Ignore this girl and find someone else. She doesn't sound decent to me