How do I use the control callback when creating a simple dashboard plugin

On this page: http://codex.wordpress.org/Function_Reference/wp_add_dashboard_widget

The function wp_add_dashboard_widget is described.

It states:

wp_add_dashboard_widget($widget_id, $widget_name, $callback, $control_callback = null)

How do you use the $control_callback, properly? I am completeley stuck, as I have defined it but cannot use it.

I need to create a form within this widget which is why I am using the control_callback.

EDIT: as a side note I am using WordPress 3 and Multisite

Solution : hover on the title bar of your widget, then click configure

Don’t ask me why this works like this but it does.