You're really that uncomfortable with it? Are you in a relationship/married and is she crossing that line? Does she know you're married? Does she know you're that uncomfortable?
People flirt. It happens all the time. Take a little pride in the fact that a girl finds you attractive. But if you're really, REALLY that uncomfortable with it, ask her to stop. Explain that you don't feel that flirting in the work place is appropriate, and just explain, kindly, that you aren't interested.
Filing sexual harassment against her is such a disgusting waste of your time, her time, and the court's time, considering it's just a crush. Come on, dude.
Now, if it persists, that's when you be more stern with her and explain that you want her to stop outright. If she persists after that, or does something especially insane, THEN file for sexual harassment. That should be saved for extreme cases.
EDIT: Oh, I get it now. You're trolling or trying to make a point.
You're not really good at it.