Save file as read-only when supervisor clicks on close

[rifleman_scar]

I would like to, (if possible), create a macro that will save a document as
read-only when a supervisor clicks on the save button. Is there a way to do
that? I am trying to create an online schedule for my department and would
like for it to be saved so that others can view the form and search for times
and dates, etc., but not change any data on the forms. Any help you can
provide would be greatly appreciated.

Thank you in advance.
Mark