You would think looking like Jessica Alba would be a pretty easy gig, but even the star herself finds it hard sometimes!

Jessica told "O.K.!" magazine that when she was preparing for her role in "Sin City", she was sure her breasts weren't big enough for the part! In the interview, she said "I saw the pictures in the comic book and thought, 'that girl has some knockers!' I didn't really understand how I was going to get such an impressive chest!"

Jessica played the role of “Nancy”, a stripper with a heart of gold. The movie “Sin City” was based off a comic book series by Frank Miller.

Though Jessica has her doubts, the rest of the world sure doesn't seem to. Jessica has been topping the polls as one of the most beautiful woman alive ever since her career began! 

Jessica worried about her routine just as much as her chest. She also said to reporters "What if I’m up there trying to be sexy and my chaps split or my top comes undone? I was worried I would fall off the stage or hit myself in the face with the rope (lasso)."

Jessica practiced for her role as "Nancy", by observing at strip clubs and then practicing herself. She says for her cowgirl-style strip tease she started out doing her routines in regular clothes, than gradually did them wearing less and less.

Well Jessica's hard work paid off in the end! It's doubtful that anybody who has seen "Sin City" will bad-mouth the actresses dancing or what was under the costume!