The TOP area always appears at the beginning of the main window. You can use it, for example, to automatically output headings on the subsequent pages for tables that cover several pages.
All output you place into the TOP area using the print program is not formatted at once, but stored internally in SAPscript first. Formatting occurs only as soon as the TOP area in the main window is actually output, that is, as soon as the print program writes text into the BODY area. Variables are retrieved and replaced in that moment as well.
If the BODY area of the main window was filled before the program reached the definition of the TOP area, this definition is used as TOP area for the subsequent page. This means, that you can no longer delete a heading in the TOP area after writing text into the BODY area.