Can't join partitions on Disk Utility, why?

Hi good guys,

I am trying to make a single partition with Mac OS Journaled but Disk Utility won't let me.

I currently have 2 partitions: MacHD with 80Gb and partition B with 3,35Gb (Partition where I used to have XP with BootCamp). I finished with XP and erased that partition to become Mac OS Journaled. Now I try to have a single partition but I couldn't.

On the Partition tab of Disk Utility, when I select the whole machine (FUJISTSU MHW2120BH) the option Partition is dimmed and won't work.

I also tried iPartition, but it tells me:
To make changes to this disk you should either boot from an external drive, use Target Disk Mode with another Mac, or create a bootable CD/DVD.
You can create a bootable CD/DVD by running Coriolis CDMaker, which should be available from you distributor.

I thought my instalation DVDs would work as bootable, but:
I tried with the Tiger instalation DVDs but it makes me chose one of the partitions to format and won't let me do both at once.

Please help!!
I feel stupid not knowing to get a bootable DVD and despered that can´t have one partition on my Mac.

Thanks a lot for any suggestion.
Regards,

 

Thanks a lot uaecasher,

I deleted XP partition, so now it is Mac OS Extended (Journaled).

There is where I got stuck. I'm sorry it seems to be something simple, I just didn't find Disk Utility from the installer.
In the Mac OS X Install Disc 1, my options are: Install Mac OS X and Bundled Software / Install Bundlked Software only / Xcode Tools /Read before you intall / Apple Hardware Test Read me.

When I Restart the machine with the Disc, I get the options to Format but it shows me the two partitions so I have to choose just one to format. I formated both separatly but even then the Disk Utility of both won`t activate the PARTITION option when I select the whole machine.

It seems that I am missing something, what could that be?
Thanks again.
Regards.