The electric resistance coils on a dryer eventually quit. They are pretty easy to replace, but you will need to get the parts. Get your model number and look up the parts at http://www3.sears.com/ . You should also see schematic diagrams that will help you disassemble and repair the dryer. While you are at it, use a shop vac to clean out all the lint. Oh, and least we forget, unplug the dryer before you install a new coil.