checkboxes: x or checkmark to indicate

I have spent a few hours trying to figure this out.

I am designing a run status report for a ski hill. The form will show the name of the run, and beside it the user can click on a checkbox that should display a green checkmark (run is open) or a red x (run is closed). This is designed in InDesign, but I am making it into an interactive PDF form. This would be used each day by ski hill operations team to indicate runs being open or closed. For the life of me, I can't get this to work. I can get one box to work, but if I use multiple boxes (many ski runs), only one will display. Any ideas?