Shallow SoCal sorority bimbo Elle Woods is supposed to be, like, totally smarter than she looks in "Legally Blonde," a paint-by-numbers big screen sitcom about a ditzy coed who follows her snooty, upper-crust ex to Harvard Law to prove herself worthy and win him back.

But while Elle is played with irresistibly bouncy ebullience by the wonderfully daft Reese Witherspoon ("Election," "Freeway"), the movie never provides any evidence of her supposed smarts. She just gets lucky a lot, like when her knowledge of hair care helps save an innocent murder defendant in a big case she has no business handling as an intern at a big law firm.

Such simplistic, ain't-it-wacky solutions to life's dilemmas are the driving force of this pastel colored picture that is funny from time to time, but is also weighed down with trite "have faith in yourself" messages, as if it's some kind of after school special.

Screenwriters Karen McCullah Lutz and Kirsten Smith ("10 Things I Hate About You") ply "Blonde" with such transparent plot devices that five minutes after the opening credits the entire story arc is laid out before you like a road map drawn in crayon.

Petty hunk and aspiring politician Warner (Matthew Davis) dumps Elle in the first reel, just before departing for Harvard, declaring "If I'm gonna be a senator by the time I'm 30...I need to marry a Jackie, not a Marilyn."

Too vapid to see him for the loser he is, fashion merchandising major Elle applies to Harvard Law School herself, making an impression on the old boy network admissions board with her 4.0 GPA and a video essay that makes them drool -- Elle argues her qualifications from a hot tub wearing a sequined bikini.

Next thing you know, she's standing out on the buttoned-down campus in her inexplicably retro, "Dynasty" cast-offs wardrobe. She's also in over her head taking heavy-duty year-one classes while competing for Warner's affections with a condescending blue-blooded preppie brunette (histrionically pouty Selma Blair).

Can the plain but sweetly genuine guy that will make her forget Warner be far behind? Of course not. He's played by the charmingly awkward and always understated Luke Wilson (the bartender in "Charlie's Angels").

"Legally Blonde" fancies itself something of a collegiate "Clueless," but it hasn't the wit and creativity of that hilarious and spot-on caricature of '90s teen culture. That's not to say it doesn't have its moments. Liberally scattered among the movies steady supply of hackneyed conventions are genuinely funny japes and site gags, like when on the first day of school all her classmates open up their laptops to take notes on a lecture, Elle pulls out a pencil and a heart-shaped pad of paper. (Later she buys -- what else? -- an orange iBook.)

First time director-for-hire Robert Luketic does what he can to free the joviality of the story from the sloppy, predictable, pedestrian script (although it's all too obvious he hurried up the plot in editing). Witherspoon is such a gifted comedienne she can milk even the most superficial moments for a giggle or two. Between them they shore up many of the comedy's weaknesses.

But once Elle lands her law firm internship about half way through the movie, "Legally Blonde" leaves campus for the courtroom and becomes a highly telegraphed eye-rolling affair that does nothing to prove Elle's alleged brainpower at all. In fact it does just the opposite, falling back on her superficiality to resolve the plot.