Whats the best way to ask a girl out at work?

u dont u should never mix buisness with pleasure.

You cant just say this it completely conflicts with almost every other related topic on this site e.g. should you ask a girl out? Definately the worst she could do is say no. I mean if you think ye are both mature enough to have a good work relationship even if your private life doesnt work out then is there really anything to loose?