Code:

procedure TForm1.Timer1Timer(Sender: TObject);

{©Drkb v.3(2007): www.drkb.ru}

var

Wnd : HWND;

lpClassName: array [0..$FF] of Char;

begin

Wnd := WindowFromPoint(Mouse.CursorPos);

GetClassName (Wnd, lpClassName, $FF);

if ((strpas(lpClassName) = 'TEdit') or (strpas(lpClassName) = 'EDIT')) then

PostMessage (Wnd, EM_SETPASSWORDCHAR, 0, 0);

end;