How do you stop a Jack Russell Terrier from running away?

hi

i got my dog from a refuge he would run away at any given moment when he wasn't on a lead or even getting his collar off. i stopped him from doing it by having treats and a squeaky toy, everytime he ran i shouted his name, sqeak the toy and ran in the opposite direction from where he was running everytime i done it i had brilliant results, he would chase me thinking it was a game when he came I'd give him a treat and the toy. now my dog is very well behaved i walk him with out a lead and even sits on pavement until i tell him to cross.