bootcamp problem

i installed bootcamp and windows xp but now im stuck in xp and cant get back to mac
already tried the holding fn button down while starting the mac
plz help

EDIT: ups found out pressed the wrong button... (it almost scared me to death just the thought of being stuck with windows)

There is an icon down by the clock in XP that you can click and it allows you to reboot into the Mac OS as well.

hold down option button on restart