I was a co-signer on a car loan for my friend he paid all the payments on time for a year, but now no payment ?

i was a co-signer on a car loan for my friend he paid all the payments on time for a year, but he has not made payment for about a month, plus hes moved out to another state.. what can i do to get hold of the car becasue i tryed calling him and he doesnt answer my calls.. plz some one with good knowldge help me!!!!