Do you believe in being "Hypnotized"?

hey.. I went to this fair in my town and there was a stage hypnotist... he called people up at random including my best friend. he didnt chose me i am kind of annoyed lol. well when they were on stage he just said like "you will be relaxed bla bla" and he went over and touched a part of them and one by one they all fell off the chairs. and he made them all do stupid things!!! i saw my friend barking like a dog!!! i mean it seems soooooooooo fake! but i could never imagine by friend barking like a dog on stage shes so shy! do you think this was all an act or can a person become that unaware and hypnotized that quickly on stage?