Boot camp problem

I installed boot camp and it worked fine and everything and then I went away for vacation for 2 weeks and my Mac was left on the whole time. My Mac was running a little wierd when I came back and I rebooted it and now when I hold the option button it won't do anything but boot directly to Windows. I've tried everything, putting in the Mac OSX install disc, holding down more than one button, booting up into Windows XP and shutting it down from there, I don't know what to do.

Can you get to OS X by booting into XP then selecting OS X by going to the boot selector thing in the control panel that got added when you installed the bootcamp drivers?

It worked, thanks!