I just bought an iphone (I bleieve it is firmware 1.1.3 - not sure)

I have still not connected it to my computer. I tried the 1.1.1 out of the box jailbreak and after a few tries it said something about EDGE and it's still locked.

Can anyone advicec me on how to go about this?? I am using T-mobile and would like to use my iphone on that network