Because

BECAUSE THEY'RE YOUNG-1960-American Bandstand's Dick Clark (who died in April 2012 at 82)  is a new high school teacher. His students include a loving couple (Doug McClure & Roberta Shore; 5 years later they would both co-star on TV's THE VIRGINIAN) who want to get married, skinny Warren Beringer (who later became a pudgy TV character actor) who doesn't know his mom's a floozy, bad boy Riff Rimer (Michael Callan) and his ex-girl friend Anne (Tuesday Weld) who has a nagging mother. Chris Robinson (later the lead role in STANLEY) is a toughie who tries to cause trouble at a dance where James Darren and Duane Eddy (who also does the theme song) perform! 


Riff gets involved in a hold up staged by his butcher shop boss. Lying and misunderstandings (and a knife fight) follow but the man who made lip-synching fashionable on music shows straightens out everything in the end. 


Also with Victoria Shaw (who was Maria Van Braun in I AIM FOR THE STARS the same year) as Clark's love interest, Phillip Coolidge, Bess Flowers and John Zaremba. It's based on a novel called "Harrison High". 


The year before BTY director Paul Wendkos had directed the original GIDGET (and would also make its two sequels) but later devoted himself mostly to TV. 


Thanks for reading!