Aloha,
Thanks to those who have already responded to my Staffy's problem. I guess in all fairness to my obidence instuctor who recomended that I whack my dog across the nose with a rolled up magazine, I needed to mention that it was supposed to be a (1) one time only hit. It was tried by her on some other aggressive dog that was giving problems to another owner and was used as a last resort. She said it worked with a very aggressive "Rotty" and the dog graduated off leash. Again, it was just a suggestion. The hitting of the nose wasn't suppose to be everytime my Staffy got aggressive towards another dog. Also, although my Staffy is 5 years old, I just got him about 6 months now and he is very well discibline on walks and on and off leash as long as another dog doesn't bark at him.
Understand that my Staffy is not aggressive to all dogs and that it doesn't matter what breed or size they are. He's only aggressive if challenged and I never know when that is except by his signals when another dog gets close by. I'm beginning to recognize them a lot quicker now and I do re-direct his attention or make him sit. The thing that gets me really angry when walking with my Staffy is when the owners of the other barking dogs don't do anything to correct their dogs who started the barking and they are standing right there. Mahalo and thanks for all the advice and comments.