When you create a new window in PowerBuilder, its default window type is Main. Select mdi! or mdihelp! on the General property page to change the window to an MDI frame window.
Using menus
When you change the window type to MDI, you must associate a menu with the frame. Menus usually provide a way to open sheets in the frame and to close the frame if the user has closed all the sheets.
About menus and sheets
A sheet can have its own menu but is not required to. When a sheet without a menu is opened, it uses the frame's menu.
