Lead Dog

People who let their dogs off leash in dog parks, is to train your dog, not how to run two other dogs?
My Way 5 months old cousins staff almost every day. I walk in a park full of that dog walkers. Most of the time the dogs are off the track, running and paying each other. Im the little dog is really good leader and he's very playful with other dogs. Yet how I can train him to not see a dog run after him to play because not all dogs are playful?
Most people who are used to walking their dogs off leash dogs does not take aggressive or dogs that are prone to starting fights. Most dogs that are walking in pubic are well socialized and used to meet dogs and people new. Sometimes an older dog will be a younger dog is a verbal warning. Management can cut the dog, but this is not to start a fight, it's just to say "Hey get the heck out of my space !"… Dogs communicate well, and if a dog does not want to be bothered by another dog, give him a message. Also can train your puppy to "leave" … do a search on yahoo and find good free information on this topic.
How to stop your dog pulling his lead – Barking Mad – BBC Pets