[gtkmm] How to get the value of selected row?

[Akbar <linux cwazy co uk>]

I have Gtk::ListStore that display my wallpapers list like this:
/home/knight/wallpaper/wallpaper11.jpg
/home/knight/wallpaper/wallpaper12.jpg
/home/knight/wallpaper/wallpaper13.jpg
/home/knight/wallpaper/wallpaper14.jpg

My declaration is like this:
        class ModelColumns : public Gtk::TreeModel::ColumnRecord {
            public:
                ModelColumns() {
                    add(m_col_no); 
                    add(m_col_wallp);
                }

                Gtk::TreeModelColumn<unsigned int> m_col_no;
                Gtk::TreeModelColumn<Glib::ustring> m_col_wallp;
        };

ModelColumns m_Columns;

Glib::RefPtr<Gnome::Glade::Xml> m_refGlade;
Gtk::Image *m_Picture;
Gtk::TreeView *m_TreeView;
Glib::RefPtr<Gtk::ListStore> m_refTreeModel;


My m_TreeView is like this:
    m_refGlade->get_widget("treeview1", m_TreeView);
    if(m_TreeView) {
        Glib::ustring filepath =
"/home/knight/.wallpapoz/wallpapoz.xml";
        int i = 0;
        xmlpp::DomParser parser;
        parser.parse_file(filepath);
        m_refTreeModel = Gtk::ListStore::create(m_Columns);
        m_TreeView->set_model(m_refTreeModel);
        xmlpp::Node* pNode;
        xmlpp::Node::NodeList list;
        xmlpp::Element *el;
        xmlpp::TextNode *t;
        Gtk::TreeModel::Row row;
        if(parser) {
            pNode = parser.get_document()->get_root_node();
            list = pNode->get_children();
            for(xmlpp::Node::NodeList::iterator iter = list.begin();
iter != list.end(); iter++) {
                el = dynamic_cast<xmlpp::Element*>(*iter);
                if(!el)
                    continue;
                t = el->get_child_text();
                if(!t)
                    continue;
                row = *(m_refTreeModel->append());
                row[m_Columns.m_col_no] = ++i;
                row[m_Columns.m_col_wallp] = t->get_content();
            }

            m_TreeView->append_column("Workspace", m_Columns.m_col_no);
            m_TreeView->append_column("Wallpaper",
m_Columns.m_col_wallp);
        }

    }


My Image displayer is like this:
    m_refGlade->get_widget("picture", m_Picture);
    if(m_Picture) {
        //This is where I stuck......
        //How to get the selected row 
        //row2 = how.......????
            Glib::ustring temp = row2[m_Columns.m_col_wallp];
            m_Picture->set(temp);
    }

How to get the value of selected row????? When you select for example:
/home/knight/wallpaper/wallpaper14.jpg
My Gtk::Image wallpaper will display the picture in right of
Gtk::ListStore.........
Please, help me????