Just be there for him/her. Listen, understand, love. That's all you can do. Whatever you do, DO NOT tell them everything will be ok, because, unless you can guarantee that it will, it's both useless, and a cop out, and in the end can really piss him.her off inside. Whetever you do, don't give unsolicited advise. None of us are really qualified. Insteat of trying to "fix things", try just being supportive, and understanding.