What should i do next if i messed up trying to shrink a disk with disk utility

Question

i wanted to make a back up disk for my macbook. couldnt use time machine because time capsule had trouble with airport. went to disk utility, only had 1 disk on entire hard drive. it was Macintosh hd it was 160 gb and had just under 40 gb space used. it said this disk is the start up disk and cant be erased. i clicked on the bottom right hand corner of the partition box slid the resize bar up and clicked apply. when it finished "resizing" disk it said resizing failed. i knew about 2 seconds after i clicked apply that i had done the wrong thing but didnt do anything until it was done. i can slide the size bar up and down and my mac book is still working fine. i need to know if i should restart it from here or if there is something else i should do in disk utility first to be sure that my hard drive is back to the same size it was before i placed my entry in the bone head of the year contest. lol.
Model Name: MacBook
  Model Identifier: MacBook5,1
  Processor Name: Intel Core 2 Duo
  Processor Speed: 2 GHz
  Number Of Processors: 1
  Total Number Of Cores: 2
  L2 Cache: 3 MB
  Memory: 2 GB
  Bus Speed: 1.07 GHz
  Boot ROM Version: MB51.007D.B03
  SMC Version (system): 1.32f8

Answer 1

Ok, so first things first:
Why do you think you need to "shrink" your hard disk?
If it's because you want to make a backup, it is a very bad idea to make a backup on the same disk you use as a startup - why? Because if/when the disk fails (and all hard drives will at some point), then you not only lose your startup, but your backup as well.
Not sure where you're at at this point and which steps you've taken, but doing anything else may result in your drive being wiped. So, do you have a backup that works? If not, get an external hard drive, format it Mac OS EXtended (Journaled) with the GUID partition schme, and back up your entire disk either using Time Machine or making a bootable clone using CarbonCopyCloner or SuperDuper. After that we can address resizing your hard drive (as your screenshot shows right now that you've shrunk your hard drive to less than 40 GB - I'd simply quit Disk Utility and do not save the changes you were making if it's still open).