Chemistry lessons

Chemistry lessons

By Geoff Berkshire
Metromix

Is Katherine Heigl a TV star, a movie star or both?

She's already got an Emmy for mega-hit medical series "Grey's Anatomy" and a summer blockbuster ("Knocked Up") under her belt, but the real test of her star power comes with the Jan. 18 release of "27 Dresses."

Heigl's hardly the first female TV star to make a bid for movie stardom via a romantic comedy (and she won't be the last—Eva Longoria Parker's "Over Her Dead Body" is due out in February), but the track record of success for some of the small screen's biggest names has been mixed.

Check out how Heigl’s predecessors have fared in their attempts at “chick flick” success...