PRO DC - Help creating 2 dropdowns and 1 text field (auto populate w/ ability to edit)

There are already so many answers to these questions on the forum.

As 'Custom Validate' script of "PETS" dropdown, use this:

var type = this.getField("TYPE");
switch(event.value){

case "Dog":
type.setItems(["Lab","Poodle"]);
break;

case "Cat":
type.setItems(["Saimese","Persian"]);
break;

default:
type.clearItems();}

 As 'Custom Validate' script of "TYPE" dropdown, use this:

var trait = this.getField("TRAIT");
switch(event.value){

case "Lab":
trait.value = "Friendly";
break;

case "Poodle":
trait.value = "Smart";
break;

default:
trait.value = "";}