How can i reduce or get rid of the squeak from my box spring and mattress?

Most box spring noise, results from a loose staple holding the "spring embly", to the wooden frame embly. My solutions to similar problems, requires, opening the bottom of the box spring unit, to inspect the interior of the unit. to do that, carefully remove the staples around the parimiter of the box frame, pull back the fabric to expose the underside of the spring embly. carefully check where the metal frame touches the wood (usually where the noise comes from) when you find the loose staple, attempt to re-set the staple, (hammer it back down) or add another "like type staple". you could also have the wooden frame parts loose, requiring tightening loose joints, with glue/screws, and maybe some backup pieces of wood lath, to make the joint stronger. Actually, the least expensive solution, would be to replace the box spring with another. Don't worry about different fabric, just get one the same size, preferrably made by the same manufacturer. Check out some of your local discount mattress companies, they are always discounting mis-matched units