Windows partition went wrong, wont boot to Mac OS X - HELP!

Okay, forgive me if I confuse any of you with my in-depth story. Here it goes:

I recently bought a brand new 13' MacBook Pro 500GB (MBP). I partitioned 50GB of it for Windows XP. Today I decided I would install windows on the 50GB partition. This is where it gets ugly.

I am going through the steps, Enter, Enter, F8 to agree to terms & conditions, etc. I get the to part where it shows a "Partition1 [unknown] and it wants me to format it before I can install Windows XP. I have done this before and accidentally wiped my dad's 500GB iMac (he had everything backed up via. time machine - phew!). I am very cautious and instead of formatting the (131000MB FREE - does that look right?) HD, I press ESC and quit.

My Mac reboots and it automatically goes to the blinking "_" underscore (DOS?) and I get nervous. I reboot again holding down "option". It should show OS X and WINDOWS but it only shows WINDOWS. I put in my Snow Leopard install disc and it keeps freezing. Then I realize that I may be using the wrong disc, so I put in my "OS X Install Disc 1". Every time I put it in and select it, it simply freezes and I am forced to reboot.

WHAT DO I DO!? I would really like to get my MBP back in working condition, and I also would like to know WHAT I did wrong.

Thanks in advance!

 

THANK YOU SO MUCH! I was using my iMac disc instead of my MBP disc. I am pretty sure I didn't wipe the hard drive since it only took about 30 seconds. I am at the "Install Mac OS X" screen, but I CAN go into utilities, etc.

What do I do from here?

 

More info: When I go into Disk Utility, there is not "Macintosh HD". Only a 500.11 GB ST9......."

What do I do?