carb loose on engine, help

[rondoolaa]

hi guys,

had a mess about with my hpi trophy truggy today and to stop the engine i normally pull off my air filter and put my finger over the air intake hole on the carb but today when i pulled the air filter the carb came off in my hand, i pushed it back in and car started straight away again but when i accelerate the carb moves which i am sure it shouldnt,

my question is, what holds the carb in place in the engine, is it just some rubber gaskets or such or is it some type of sealent or is there a bolt,

am unsure how to stop the carb from moving,

any help appreciated,

thankyou,

ron