I think I have told this joke on here before, but oh well.
A blonde, a brunette, and a redhead are in an elevator. A man enters. The women notice that he has a lot of dandruff in his hair.
"Damn that's a lot of dandruff!" says the redhead.
"We should give him some Head and Shoulders!" says the brunette.
"Okay!" says the blonde, "But what's shoulders?"