i have just got a westie he is 16 weeks old and is getting over excited and is biting. tryed lots of thing to stop him but nothing seems to work. help....

At 16 weeks he's probably learnt something from his previous home - did you get him from a breeder where he was kept with his litter mates and mother/other dogs? Or from a family who had him as an 8 week old pup?
What methods have you tried so far? Often it's a matter of using one tried and tested technique and sticking with it - ensuring the dog is getting no reward for biting, and plenty of reward for 'playing nicely' ;-)