Understanding Scroll Areas, Scroll Bars, and Grids
A page must reflect the underlying table structures so that the system knows where to store data in the database. When you have more than one underlying record definition on a page, the role of scroll areas, scroll bars, and grids in page processing is important. Scroll controls and grids define parent and child record definition relationships on a page.
You assign an occurs level to each scroll control or grid on the page to indicate the relationship between the record definitions and the controls and to determine how the data is processed. The primary record on a page at level 0 has no scroll area or occurs level associated with it. If the page contains a record that is subordinate to the primary table, it has a scroll control with an occurs level of 1. A table that is subordinate to the level 2 record has a scroll area or grid with an occurs level of 2. PeopleTools does not support nesting beyond three levels.
PeopleSoft Application Designer automatically nests the scroll area after you set the occurs levels sequentially. Each field that you place on the page after each scroll area is automatically placed inside the scroll area preceding it until you place the next level-based control on the page.