Linda, If the gains from sales of position held for a year then the tax I believe for federal will be capital gains of 15%. I don't think that there are state or city capital gains taxes. Other wise if the position where held for less than a year then the gains are at regular rates the highest of which is 35% I think. They have changed the rates twice on me now thanks to President Bush.
On the Tax Problem this: Uncle Sam is your legal Partner on earnings. Fair enough, if you approve of the mistakes your partner makes without consulting you.
On your losses Uncle Sam is not your Partner! Losing money you have to do all on your own!