menu from glade

[Michal ROMAN <michal roman nov sk>]

I create menu from glade file :

xml = glade_xml_new (file, rootnode);
menubar = glade_xml_get_widget(xml, rootnode);

Then I add some data to all items :

item = glade_xml_get_widget (xml, item1_name);
gtk_object_set_data (GTK_OBJECT (item), "data", g_strdup(data));
...

How can I free this memory at the end of my program?
Or how can I find item in GtkMenu?

Thank you.
Michal