In a graphical user interface, a simple window containing a title bar, a message, and one or more response buttons. This kind of window will normally allow no other actions to take place until a button has been pressed. In the simplest case a single button marked ‘ok’ is pressed to acknowledge the message; in other cases there may be a choice of buttons such as ‘yes’ ‘no’ ‘cancel’ or ‘replace’ ‘create backup’. Dialogue boxes may contain more complex objects such as radio buttons, pull-down menus, or scroll bars.