Preview Record when hovering over a column

If I'm understanding this, it sounds like you only need to use the built-in features:

1. Create a link between the two in the TABLES page and set it to display in popup.
2. Select the field(s) you want displayed with the PAGE DESIGNER for the detail table and rename the link to be whatever you want on the master table. If you need the popup to display something different than the full details page (maybe abreviated) , then create a second list page on the details PAGE DESIGNER with only those fields and on the master page detail link, point it to that form instead.

Hope that helps.

Thank you for your response, however that is not what I am looking for. I would like the value of a HTML field in the detail record to appear in a pop-up when hovering over - not clicking on - the master record.

For example, a pop-up of line items on an invoice would appear when hovering over an invoice number on a list page.