get over it. Plenty of fish in the sea. Don't waste your time.
Ask her if she'd like to go out, and if she doesn't, it's not the end of the world. Or, you could do the easier thing and go for someone else.
if you asking that question, it's already to late
I like this girl who is going out with this other guy, yet, on the way home with another friend of mine, he told me that this guy liked someone else, and a few weeks ago I in person heard him say he didn't like this girl (even though they'd been going out and still are).
you tell her that things aren't really working out so you break up then in like a week you ask out the other girl you like
deal with it
Ask the other girl out unless you think your girl is angry!
You show him that your better then the other girl
Why are you? Don't - if you can, drop them.
It might be hurtful, but it's not necessarily a bad thing; she may not like you or like someone else better. It's better to know sooner than later.
Ignore her and go out with someone else
If this girl can't see that you like her, she's probably not worthing dating.
As long as you genuinely like that someone a little bit, it is OK if you like someone else more. I am going out with someone, but I like someone who is way out of my league.