IDA Help: get_frame_id

Get ID of function frame structure
     ea - any address belonging to the function
returns: ID of function frame.
         In order to access stack variables you need to use
         structure member manipulation functions with the
         obtained ID.
         -1 if function or function frame does not exist.

#define get_frame_id(ea)  get_func_attr(ea, FUNCATTR_FRAME)