Rooting without a computer is risky business. Much can go wrong and will leave you with a paper weight until you get to a PC and try to find out the solution and hopefully it's fixable.
Give this Blog,
No Magic in Rooting, a read and make sure you understand a few things.
Also read read and read some more about rooting your device and understand what you are doing to your device or the above warning about having a expensive paper weight could very well be the outcome.