Hi, I need some help fast, my iphone 4 is from verizon and it had 4.2.8 and it was jailbroken, but something happen today, I plug into itunes and it said something about 4.2.10 and it started, but I unplug my phone, so I lost cydia and now my iphone won't start up, it is black and I have tried to push the top button and the home button, but nothing. I have also plug it in to itunes, and it doesnt show my iphone. Help me someone, please...