so a man walks into a bar with his dog..

and the bartender says " sorry, you can't bring your dog in here, i don't want to clean up after him"
the man says " its ok, the dog is trained" so he lets him in

a second man and his dog walks in, and the bartender says " sorry mate, you can't have a dog in here" and the second man says "he's trained its ok" so he lets him in

then a third man walks in with dark glasses and a dog, the bartender says "hey man, i don't know what your doing but you can't bring the dog in with you" and the man replies " but I'm blind, i can't move around with my seeing eye dog!"
the bartender says " mate, there is no way that chihuahua is a seeing eye dog"
the blind man looks confused and says "hold on, they gave me a chihuahua?!"