Iphone 3gs got switched off while jailbreaking and not getting switched on?

I have jailbreaked my iphone 3gs with redsnow. During the last step of process in DFU mode or installing cydia it got switched off suddenly. And i tried to switch on it again. But it is not getting switched on. What is the solution for it.

During a jailbreak there's no way you would have bricked your iphone…
I think your phone is still in DFU mode… Try holding the Home button and the power button together for 10-15 seconds or until the apple logo comes…
Try it with your iphone connected to the pc and also disconnected…
Even if it switches on… Chances are that you should restore your firmware…