headlight/ brakelight problem
 

when ever i turn my headlights on and hit the brakes, my brakelights do not become brighter. they stay the same. the middle brakelight on the rear windshield gets a bit brighter but it is very faint, almost unnoticable. obviously this is a big problem because i really dont want to get rear ended when i am driving at night or in the early morning. i also dont want to drive with my kids in the car either. has anyone had this issue b4 or think they might know what might be the prob. would appreciate any help, if not i guess im going to have to go to the stealership but would like to avoid them like the plauge if possible. thanks.