A new law change from 1st October 2005 means that rather than needing to prove that someone of the opposite sex would have been treated differently in the situation complained of, you now only need to prove you yourself were treated in a way relating to your sex which violated your dignity, or was intimidating, hostile, degrading, humiliating or offensive. So if a colleague persists in making remarks about what nice legs a female employee has, or her boss promises her promotion if she goes away with him for the weekend, she should be able to claim that this is sexual harassment and ask her employer to do something about it.