(Portland, OR)  --  Portland police are still looking for suspects, after a man was beaten with a hammer during a robbery.  Authorities say the victim and another man left a 7-Eleven store at Northeast 15th Avenue and Killingsworth Street Friday when they were approached by a man with a hammer and another with a gun.  Police say one victim was beaten in the head several times with the hammer, but the other victim wasn't hurt.  Police tried to find the suspects with a K-9 unit, but were unsuccessful.