In addition to usual report pages, you can use several dialogue forms in a report. For dialogue form creation, the same designer as for report pages is used. The  button in the designer toolbar is used for creating a new form; it adds a new page into a report. When switching to the page with the dialogue form, the designer workspace changes, thus becoming a form where objects (i.e. controls) can be placed:

It resembles the Delphi environment, doesn’t it?