99 and 00 both had usd forks, and the plastics are identical! if your bike has a 38pwk keihin carb , with an electronic powerjet then its a 99 model.
the other true fire way is to look at the date stamp on the wheels, all 2000 models had a date stamp later than 7 99 , if your bike has stamps on the wheels between 9 98 and 6 99 its a 1999
position of the cdi unit is another give away, also the casting number on the suspension linkage.but these couple of tips should sort you out as to exactly what year it is.
previous post regarding seat/forks/front plate/pipe info is all incorrect, this refers to 1998 models and 2001-2006 models
cheers, Colin.