Every time she walks through it, the alarm sounds, and she's asked to remove another article of clothing.
Pretty soon she's down to just her bra and a few other things and the airport screeners (played by Kevin Nealon, Dana Carvey and Rob Schneider) are saying stuff to her like, "Now, arch your back for more security."
I don't think it's on YouTube or else I'd post it. It's a classic.
This story also reminds me of the "buh bye" sketch with David Spade.