I've been trying to smoke on my five burner gas grill for a couple years now with not much luck. I just can't seem to get the placement of the smoker box in the right place. I place it on top of the grates and it doesn't "smoke." So, I put it on the gas flames and it's burned up in just a few minutes. I usually get frustrated and end up cooking the meat in the oven. Any advice would certainly be appreciated. Thanks.