I want to be a web programmer [when I grow up?] because it's what I like doing, and I really do thoroughly enjoy it (web development in general, actually). I have about 2 years experience with PHP, CSS, and HTML and a few months experiance with JS and jQuery. I've been wondering this for a while -- what languages should I be most familiar with if I want to try and make a career out of web development? I'm only 17, so I've got plenty of time, and I think I've got a decent headstart on things, but it doesn't hurt to ask.
If I'm thinking in terms of being able to get hired as a web programmer, what is (or what are...?) the most useful thing I can do now to be able to have an upper hand when it comes to looking for a job. What languages, as a young programmer, should I really focus on? If you were looking to hire a developer, what would you be looking for?