Boot Camp partition won't delete?

When I try to delete my boot camp partition on my 500GB Macbook (Running OSX10.8.3), it comes up with an error, regardless of whether or not I use Disc Utility or Boot Camp Assistant.
The error messages are here, in screenshot form:
imgur: the simple image sharer
What do I do to delete the partition? Is there some kind of way to force it to delete?
Thanks in advance.

Are you booting the machine to the Recovery Partition first, and then trying to remove the Boot Camp partition using Disk Utility? If that doesn't work and the disk refuses to unmount, you may have to use a boot disk and run Disk Utility from that instead.

chscag said:

Are you booting the machine to the Recovery Partition first, and then trying to remove the Boot Camp partition using Disk Utility? If that doesn't work and the disk refuses to unmount, you may have to use a boot disk and run Disk Utility from that instead.

Click to expand...

Ok, I will try those, thanks, mate.