object trigger related

Hello. 

On the base layer of a slide I have a list of 7 check boxes. I would like to add a trigger such that when all seven items are checked (so state = selected) layer #1 appears. 

It is possible that a learner will check the boxes out of order, so I am not sure where to place the trigger (i.e, what action will trigger the trigger!)

In addition, I have a second layer that I want to show when any of the check boxes are unchecked (so state = normal). 

I initially inserted a button on the base layer and set up 2 triggers using conditions such that if all boxes are checked, clicking the button will produce layer #2, OR if any boxes are unchecked, clicking the button will produce layer #1.

However, no matter what is checked or not checked, layer #2 is always the one that shows up. Hence, my initial question above (I would like to add a trigger such that when all seven items are checked (so state = selected) a layer appears.)

Thanks for any thoughts,

Adena