High School Musical star Ashley Tisdale can't help but laugh when she is compared to her on-screen drama queen character - because she is "shy and quiet" in real life.

The 23-year-old, who plays show-off student Sharpay in the hit films, admits she couldn't be less like her alter-ego - and being approached by adoring fans leaves her flustered.

She tells Wenn, "I'm really shy and quiet and usually when a fan comes up to me they're very nervous and shy and quiet.

"So they don't know what to say, I don't know what to say, so I'm like 'You want an autograph?'

"You never get used to it (being famous). It's so amazing."