Sounds like the battery is totally dead. It may not take a charge and will have to be replaced. Has the bike been lying for a while?
If the battery takes a charge you may be able to resurrect it by cycling it, ie. charging and discharging several times. To discharge it I'd suggest you leave the bike's lights on until the battery drains. (but not totaly flat! a tough one to figure without a voltmeter)
Probably your best route is to buy new battery and buy an optimiser which keeps the battery healthy even when the bike isn't used.
fatspark
April 2005