LUA stack values to API?

["terenctb" <terenctb@...>]

Quick question, lua uses the 'stack' for passing paramters back and 
forth.. that's how we pass stuff to the API..If I pass 3 parameters 
down to an API from lua is it the responsiblity of the API to pop 
those values off the stack...clearing it?....I know the API 
lua_tonumber doesn't seem to pop the values off the stack...after 
running a while, won't the stack just implode or how does lua do 
garbage collection?


Terence