Execute script on page change or scroll

I have multiple text fields on each page of a document.  The text fields can be populated through a generic script, from a list of predefined narratives (unique for each group of "x" fields >> i.e. the fields are in groups of three that share narratives) or can be edited in place.  The document highlights the "active edit" text field by changing the background color for the user.

Problem:

When user leaves the page, the highlighted field is not visible.  If the user selects from one of the narratives in the list for the (now) visible group, the event will overwrite the text in the last field selected.

I want to "de-select" the field if the user scrolls away from it being visible.

I understand that there are no page change events.  Can a scroll event be used, and where?  Looking for suggestions.THX!