This topic describes navigating among windows with the Accessibility API.
If the window is not a frame window, then the NEXT and PREVIOUS calls return S_FALSE and an empty VARIANT. This return indicates that there was no error, and that there are no more siblings in that direction. FIRSTCHILD and LASTCHILD calls return the one and only child of the window. The child window is a pane (BODY or FRAMESET). If the window belongs to a frame, then the NEXT and PREVIOUS calls return the frame sibling in that direction. If there is no sibling in that direction, then the call returns S_FALSE with an empty VARIANT.