WHere is IAC valve??

I have a 1999 Ford Explorer Sport, 4.0L SOHC engine...
Can anyone tell me where to find the IAC valve on this truck? I think it's what's causing my truck to no longer idle. The truck runs fine while the gas pedal is pushed but not once it's let go. ANy help is greatly appreciated!!

It's that cylendrical silver thing, with a cable pluged into it, under the large central cover(where the carburator used to be).

Found it. Thank you very much! i hope this fixes my problem!