How do you stop a dog from urinating on porch?

Usually, when they pee in a place u don't want them to, you can gently hit them on the head, and say no, and show them where they have to pee. You have to keep on doing that, until the dog finally stops that, it takes a lot of patience! Usually, its easier to learn a puppy, than an already-grown dog. The only time most dogs will urinate on the pavement is beside a pole or fire hydrant that another dog has left it's markings on. Take the dog to a park or grassy area (clean up any doo-doo your dog makes ... you can buy the plastic tissues for this, or get a pooper-scooper from any vet store and throw the poop in a bag.) Dogs love grass and playing. If you live in an area where there is little grass and it's too dangerous for you to go to a park or don't have one near you, then you'll have to put up with it. NEVER hit your dog. If you want them to stop a bad habit get a clean spray bottle and put cold water in it. First tell the dog 'no' firmly and if they persist on doing something they shouldn't squirt them in the face with the cold water. They get the picture pretty fast.