How to make a hero disabled out of stock +rep

[Shanghai]

I need this for my aos. So when u choosed a hero in any of the taverns or get a random hero. That when that player choosed a hero all other heroes get disabled for that player. So they look disabled like DISBTN. Is it sumthing with stock maximum or what ever. I have seen it before in maps and it was like that before on my map when i choosed a hero the other got disabled not all but some of them where disabled :S so how i do this :/

 

[Djinn1995]

• Actions
  • Player - Limit training of Heroes to 1 for Player 1 (Red)