This is my mom's favourite movie, she made me watch it when I was a kid, and I laughed so much I still remember the feeling - almost immediately I wanted to learn how to use a trumpet and wanted to be in a band... and this is how I got into music! :)
The Errand Boy is a 1961 American comedy film directed, co-written and starring Jerry Lewis.
Paramutual Pictures decides that they need a spy to find out the inner workings of their studio. Morty Tashman (Jerry Lewis) is a paperhanger who happens to be working right outside their window. They decide that he is the man for the job and hire him on the spot. He bumbles his way through a series of misadventures, reporting everything back to the corporate executives.