I have a page item that is set to value 5 on page load,
I have an IG below it where the users can add rows to it and save it. The first column of the IG is an LOV like this

if the user selects a test with NULL rating, page item value should not change, BUT if the user selects s test with rating value, the value of the page item should go down by one.
Is this even possible to do??
Any help is appreciated. Thank you