How do you limit the number of custom heros in a custom map?

I have 2 different custom heros per player and don't want them to be able to purchase more. The map is a castle defense style map. The trigger "melee game - limit players to one hero per type" doesn't seem to work. Anyone have any ideas?

Thanks, JAKCali

Create a trigger for when they start to train the Hero to disable training of that unit (with another to enable if they cancel) or get GoldenUrg's editor patch (http://goldenurg.tripod.com) which adds an action to limit the number of a unit-type a player can own.

Thanks, Goldberg's editor patch worked great.