The actress portrayed Sharpay Evans in three High School Musical movies between 2006 and 2008, but she won't be back for director Jeffrey Hornaday's upcoming fourth film.

Ashley admits it has been difficult to shake the perception that she's anything like Sharpay in real life, and she feels returning to the Disney franchise which helped launch her career will be a big mistake.

"It's been challenging," she tells New You magazine. "I think people in this business put you in a box and label you for what they think they know of you and what character you have played.

"Sharpay was such an awesome character, but at the end of the day, it was a character, it wasn't me. Anything that I've gotten since then, TV-wise and movie-wise, is me really fighting for it. I think that journey is what makes me so grateful for everything. If I was handed stuff all the time I don't know if I would be the person I am today."

And she has grave doubts about the success of Disney's next High School Musical venture, fearing the timing may be all wrong for a fourth TV movie.

"Looking back, it was such a perfect thing for its time and was so pure that I just don't know how you go from there," she explains. "High School Musical didn't make us, we made High School Musical because of our friendship, how close we were, and the magic there at the time. (Director) Kenny Ortega just made it what it was.

"(But) Disney is an amazing company so I'm sure they'll find some way to do it."

Tony Dalesandro will lead the cast of the new HSM movie. Its three smash-hit predecessors made stars of Tisdale, Vanessa Hudgens, and Zac Efron, among others.