About as hilarious as 50s British comedy can get, THE BELLES OF ST TRINIAN'S has almost a gag a minute... and at 91 minutes makes for a terrific time. Other films I equally recommend of the same period are THE TITFIELD THUNDERBOLT and THE GREEN MAN. In fact any film with Alistair Sim or Terry Thomas, George Cole, Richard Wattis or Joyce Grenfell or any combination is a delight. in ST TRINIAN'S we get a double dose of Sims playing two roles with that hilarious disdain he constantly lets ripple across his face. Joyce Grenfell as Ruby Gates (oh dear! that name!) plays her 'jolly hockey sticks' constable-incognito to hilarious perfection. Possibly the best laughs come from George Cole as Flash Harry (who comes out of a bush when whistled at) and various visits to classrooms by Ms Fritton (Sims) reacting to explosions ('Oh poor Betty!") or science lab gin production ("just send a few bottles of that up to my room"'). Every part of the film is funny from the characters, their costumes the antics and the setting. There were sequels but the first three are the best: including this one, BLUE MURDER AT ST TRINIAN'S and later in color THE GREAT ST TRINIAN'S TRAIN ROBBERY.