Combo Box

I would make a combo box depending on another 
In a combo box I select the state and combo box 2 as the state chosen and loaded into the combo only cities in that state. 
I thank
Hi Rafael,
Its very simple ..In simple query from which you are fecthing your cities just pass a parameter StateId which will be the selected varible of your first combo and then refresh the query on Combos OnChange event also refresh the record list.
Initially your Stateid parameter will be null and thus there will be no cities in other combo and as you select the state the and refresh th equery will start getting the mapped cities with your state.
Thanks for the help, it worked