Scripting sit action

What function do I use to have my avatar sit on an object facing a certain cardinal direction (0, 90, 180, 270)? The default has them facing the direction they came from. If there is a chair back, they avoid facing into the back of the chair, but they might face forward, to the left, or to the right when they sit on the chair. On a barstool, they sit any direction.

Cheers,
Sian

p.s. ANd while missing around with this, my avatar has been set to phantom. What the heck? How did that happen? I fall through and pass through everything, except for when I use "sit"

llSitTarget(<0,0,.1>, <0,0,0,0>; is the function for sitposition and rotation.

http://wiki.secondlife.com/wiki/LlSitTarget

The Phantom thing sounds like there is a llVolumeDetect(1); in an object you was sitting on.

http://wiki.secondlife.com/wiki/Phantom_Maker