Dryer will not stay on

[LEFT]I put clothes in my dryer today and turned it on. The dryer stayed on for a few tumbles of the drum and then shut off. I opened the door to make sure nothing was stuck, closed the door and pushed the start button. Again, the dryer turned on and tumbled for a few cycles and trned off. When I opened the door this time, there was a funny smell to the inside of the dryer. Also, when I touched the top, on the outside, it was extremely hot to the touch. I have since unplugged the dryer just in case. Can anyone tell me what might be wrong with it?[/LEFT]