NEW to wix coding, how to add limit on check boxes?

Hi Roi,
I am working of same king of problem.
Can You please elaborate how to do this:
Connect the checkboxes to the same onchange event function.

how to connect the checkboxes to same onchange function - do i have to set the property of all checkbox to onchange or something else …BTW i understand the code but this part is not cleared. …Please Guide me .