OK something might be wrong with your button or starter solenoid. Generally your starter button will either make a ground for, or provide power to, the starter solenoid. Old solenoids can seize from disuse, but they can also get too hot and go bad on a good running bike. Your solenoid will generally be located on the left or right side of the middle of the bike, under the side panels or the seat. It looks like this, or similar:
First, make sure all of your connections are good, all the way from the starter button to the starter solenoid. This includes the big power connections which run from the battery to the solenoid, and from the solenoid to the starter motor. It also includes the battery ground. If that still doesn't solve your problem, take a screwdriver and touch both of the large leads on your starter solenoid. Be prepared for a large (but harmless) spark. Your starter motor should immediately engage, so make sure you are in neutral. You can start your bike up this way if you want, and it will allow you to get home. If this is successful at starting up your bike, you may have a bad solenoid, or you may have bad wiring. Remember also that a kill switch or a safety switch could be causing this problem.