or you could get the remote number from your truck I beleive you can find this number in the glove box on a sticker. and compare the number to a some remotes on ebay. I paid $20 in ebay for 2 and programmed them myself. ALL you have to do to program them is
Press and then hold the Unlock button on the drivers side with the all the doors closed
the key has to be turned to run but with the truck off) all your locks and horn will cycle to confirm you are in program mode. Then you press and hold the unlock & lock buttons on each remote you want to program, every time a remote is added the lock will cycle
after you are done programing every remote turn the key to on and the truck will cycle the locks and sound the horn to confirm its done and thats it! hopefully that save you the money for the remote and the money to program them