I fancy a girl in work

Hi, I'm looking for a female perspective on an issue I have with a girl in work.

We are really good friends for about 6 years. About 5 years ago I started having feelings for her but she shot me down. Things were awkward for a while. Soon after she started a long-term relationship and the feelings went away. However, she split up with the guy a couple of months ago and since then the feelings have come back big-time. I'm pretty sure she still doesn't like me (although sometimes I do, but it's probably just natural for her to be real nice). She hardly ever goes out with work (I haven't been out with her socially in about 3 years), but this girl is affecting my other nights out even though she's not there. Tomorrow is a big night out and she says she may or may not go. I know if she goes I'll probably be hanging round her like a love sick puppy with nothing happening or if she's not I'll be thinking about her. Any advice please?????

Why not just ask her outright to go with you, tell her you'll have more fun if she's there?

I think when a girl says its a big no. You cant change her mind let her go and try interacting with new people and friends.