X amount of monsters destroyed transition

Is there a way when, after destroying X amount of monsters, the layout can change to a new layout? Such as if the player killed 12 monsters, the layout would swap for another layout?

Add variable monstersSlain.

Everytime you kill a monster add 1 to that variable.

When monstersSlain equals 12, go to layout 2 and setmonstersSlain back to 0.

Add variable monstersSlain.

Everytime you kill a monster add 1 to that variable.

When monstersSlain equals 12, go to layout 2 and setmonstersSlain back to 0.

Thanks!

Might want to make that >= 12 on the check incase of some weirdness that happens to cause adding more than 1 to the variable. It's a safe coding practice.