SYNOPSIS
	void notify_fail(string str)

DESCRIPTION
	Store str as the error message given instead of the default
	message ``What ?''.
	
	If notify_fail() is called more than once, only the last call
	will be used.
	
	The idea of this function is to give better error messages
	instead of simply 'What ?'.
	
	It is also better to use
		notify_fail(message); return 0;
	instead of
		write(message); return 1;
	
	Other objects will get the chance to evaluate the verb.

SEE ALSO
	add_action(E), query_verb(E)