Bootcamp troubleshot - no bootable device (?)

I had installed windows 7 on my macbook just to try it out.
It was a nice experience, and I had no problems installing it. I only found it annoying that the system made Windows7 my main OS, so whenever I started up the computer it would load windows unless I was holding the option key to select mac OSX (is there a way to change this, anyway?)
Well, so I removed the Windows partition using bootcamp as well and it made a single OSX partition.
However.... whenever I start up my laptop, it get the following message:
"No bootable device -- insert boot disk and press any key"

I presume that this is due to the system trying to start up as windows, which doesn`t exist anymore.
So, again, I have to hold the option key whenever I start up the computer, which is VERY annoying.

How can I revert this to the default settings?

Thanks!

iGuardian said:

I've had this problem too. Hold down the option key and boot into OS X, then go to startup disk in settings and change it to Macintosh HD.

Click to expand...

Thanks for your help, it seems to be working like it should now
I`ll probably install XP over bootcamp soon and will make sure to re-check this option!