From our web site:

Bulbs and Broken bulbs

Bulbs come in different sizes, shapes, colors, brightness and longevity.  Some bulbs are interchangeable, some are not.  Here's how to make some bright decisions:

• Buy name brand bulbs.  Off-brand bulbs may have the same wattage (watts say how much electricity it uses) but will not be the same brightness.  We've solved more than one lighting problem by simply having the customer use good bulbs.  Examples:  GE, Philips, Sylvania, Westinghouse.
• If you change a burned out bulb and it still doesn't work, try a bulb from a working fixture.  If it doesn't work, be sure the bulb works when you put it................................
  
  
  A lot more info follows on CFL and LED bulbs also.
  http://a-1electricco.com/hhbulbs.php