Black guy runs into see his doctor. As he is running on the spot he says,"Doc Doc I cant stop running. I run everywhere. When I should stop I run on the spot. Help." Doc says, " Here take this powder. Come back and see me in a couple of days". Black guy returns and is still. "Doc dont know what you gave me but it worked wonders. I dont run anywhere now. What was it?" Doc says" I gave you Persil." "Persil?" says the black guy. "Why Persil?" "COS IT STOPS COLOURS RUNNING"