You can monitor Ctrl+Tab or Shift+Ctrl+Tab Maybe there is some MDI interface messages related to Windows change. For more informations look here: https://msdn.microsoft.com/en-us/library/windows/desktop/ms632591(v=vs.85).aspx
-- <http://forum.pspad.com/read.php?2,64338,64341> PSPad freeware editor http://www.pspad.com
