Forms

TWindowHook is the type for the window procedure of a non-VCL dialog box. Like most window procedures, TWindowHook takes a TMessage value as an argument.  

Except in response to the WM_INITDIALOG message, the window hook should return true if it processes the message, and false if it does not. When the Msg field of the Message parameter is WM_INITDIALOG, the window hook should return false if it explicitly sets the focus to one of the controls in the dialog box. Otherwise, it should return true, in which case the system sets the focus to the first control in the dialog box that can be given the focus.  

TApplication