Harassment isn't easy to identify. The obvious kind is when a boss threatens to fire or demote you if you don't submit to his or her advances. The second hostile work environment is more nebulous: it's any unwelcome sexual conduct - jokes, touching, a raunchy photo - that creates an offensive atmosphere. The latter is more common, since many young guys don't realise that crude behaviour can become illegal, says Dr Elizabeth Fried, author of Sex, Laws, and Stereotypes. Here's how to set an offender straight.