void gtk_widget_error_bell ( GtkWidget* widget )
Notifies the user about an input-related error on this widget.
GtkSettings:gtk-error-bell setting is
TRUE, it calls
gdk_window_beep(), otherwise it does nothing.
Note that the effect of
gdk_window_beep() can be configured in many
ways, depending on the windowing backend and the desktop environment
or window manager that is used.