If you have to replace the key fob (the one with lock/unlock/panic buttons) there are online non-dealer places but based on personal experience I cannot recommend them. You can get an OEM key fob from
http://www.stevewhiteparts.com/ for $103 and they are a real Jeep dealer; other online Mopar places may have them also and it's possible a good locksmith place will also have or can get the key fob. However, that just gets you a blank key, which needs to be cut for your ignition, and the electronics, which need to be programmed to your vehicle. The former means a trip to a local lock smith or dealer. The latter means the same UNLESS you have 2 valid keys in which case there is a section on owner key programming in the owner's manual. I'm pretty sure but not positive that 2 valid keys can mean 2 "chip" keys (ones without the battery or buttons) or a chip key and a functional key fob or 2 key fobs although I'll admit to not being positive. If 2 chip keys will do and you only have 1 you might want to check with a local locksmith about getting another cut and programmmed which would put you in the position of being able to program a new fob yourself. Right now I have my 2 original key fobs and 2 chip keys (one hidden and one available so if need be I can lock the vehicle with the engine idling for turbo cool down while I get a coke or some such at a minute market while on the highway). I do know the chip key is different between 2005 and 2006 and suspect the fob is too but...
I assume you only have the one key fob? If so and if the battery suggestions I provide don't help then you are in the position of not being sure if it's a bad fob or a bad receiver. Absent that 2n fob to test the receiver you need to find some way to determine if your problem is fob or receiver. Unfortunately I cannot help with that question but would hate to see you spend $s on a new fob only to find the receiver is bad. Going out on a limb I suspect a good locksmith's or a dealer's equipment that is used to program a new key can "talk" to the receiver in which case that may be one way to determine if the receiver is good.