An alert dialog box is a special dialog box that is displayed in a graphical user interface when something unexpected occurred that requires immediate user action. The typical alert dialog provides information in a separate box to the user, after which the user can only respond in one way: by closing it. Closing an alert dialog will provide access to the original window, which is not available while the alert dialog is presented. Alert dialogs that block the application are regarded as a bad design solution by usability practitioners, since they are prone to produce mode errors. Also when used as error dialogs, they have been shown to be ineffective in their goals to inform users about an error condition or protect from a destructive operation.