def add_user(db, meeting_id, user_email, responded=False,busy_times=[]):
	"""
	@brief      addds a user to a specific collection in our mongo database
	
	@param      mongo the "meetme" database
	@param      meeting_id   a unique meeting_id, randomly generated and shared across multiple users
	            attending the same meeting
	@param      user_email (str) the users email address
	@param      responsded (boolean) "True" if the user has responed and we have their busy times, "False" otherwise
	@param      busy_times(list of TimeBlocks) busy times from the individuals calendar, busy_times will be empty if the user has not yet responded
	
	@return     None, the result is that a new user has been added to a collection in our database
	"""
	user = {"user_meeting_id" : meeting_id,
			"user_email": user_email,
			"user_responded": responded,
			"user_busy_times": busy_times
			}
	db.insert(user)
	return None