Headphone

Hi, I seem to have a problem with my iphone head phones, it has happened on and off every since day one. Sometimes when i have my headphones in the stop/play/answer button doesn't work and other times it will. Is their a certain way to get it working every time? Anyone else experience this problem? Once its working its fine until i stop listening to music and than later when i plug them in it may either work or not.

Thanks in advance for the help