How do i get my phone back to normal?

[Wumbology]

I recently tried to jailbreak my phone. But I think I did something wrong now. I just want it back to normal. But now I can't plug it into iTunes cuz it says their is no sum card installed. I have tried everything.

 

[bab2010]

Put your iPhone in dfu or recovery mode and connect it to your computer, then use iTunes to factory restore it.

 

[Wumbology]

Hey I already tried that and still nothing. But when I did it I updated it to 5.1 and used tinyumbrella and unchecked cydia. And did not download the iPad thing a 2nd time. It would be great if someone could run me thru it.