Combobox data question

[cesarjr.1991]

I've been trying everything But I cann't do it, I can do user just choise once Filtro1 or Filtro2 or Filtro 3 If you have any solution please tell me 

[RavensFan]

You took out the part of the code that determines when a choice has already been chosen.  Why?  You still have the 3 element boolean array in there, but you do nothing with it now.