Is there a cannonical 'right' way to detect single-user mode?

I'm writing an app that will behave differently depending on runlevel. I
know there's a sysctl for securelevel, but I need a way of knowing init's
runlevel.

Thanks in advance.

-- 
David Maxwell, david@vex.net|david@maxwell.net --> Although some of you out
there might find a microwave oven controlled by a Unix system an attractive
idea, controlling a microwave oven is easily accomplished with the smallest
of microcontrollers. - Russ Hersch - (Microcontroller primer and FAQ)