part_emitter_destroy( ps, ind );
This function will remove the specified emitter from the given
system and clear it from memory (this will also stop any particles
from being produced by the given emitter, but it does NOT
remove them from the room). This function should always be called
when the given emitter is no longer needed for the system to
prevent memory leaks and errors.
if part_emitter_exists(global.Sname, p_emit)
The above code will check to see if the particle emitter indexed in the variable "p_emit" exists in the give particle system and if it does it is destroyed.