Wayne,
You need to get a "pinch collar" (sometimes called a claw pinch collar), or a leather pinch collar. With a pinch collar (these are NOT choke collars) the dog is responsible for the amount of pressure he puts on himself (unlike a choke collar, where YOU are the one applying the pressure). The metal claw collars are gonna run you about $10 or so, and the leather ones will run about $25 or so. Either one will work, but most trainers like the leather one best (I've always only used the metal one). You can get one from www.lcsupply.com -- when the home page comes up, do a 'search' for pinch collar.

Doc E... Casey the PL is at www.pointinglabcasey.itgo.com