The most basic way of connecting a signal to a callback is by using %connect()% method. All classes descended from *GtkObject* have it. For example, to respond to a %'clicked'% signal on a *GtkButton* widget, you would do this: connect('clicked', 'on_ok_clicked'); ?>]]> If you wanted to connect to a class method or an object method, you have to use a special syntax for denoting that: connect('clicked', array('A', 'on_ok_clicked')); // connect to a class method $a_obj = new A(); $ok_button->connect('clicked', array(&$a_obj, 'on_ok_clicked')); // connect to an instance method ?>]]>