I just moved into an older (1924) home and have a leaky faucet/shower. I've got some home improvement books that haven't been too much help. They talk about diverter valves on top of the tub faucet or a switch above the faucet. My tub has the original ceramic knobs - separate hot/cold for the shower and separate hot/cold for the tub. That being said, how do I stop both from leaking? Do I replace the inside of the handles or...? Sorry - I'm pretty new to plumbing and I'm sure this is pretty basic.