'Shows the description in the right section
:param tv: the treeview.'

def _show_desc(self, tv):

    (path, column) = tv.get_cursor()
    if (path is None):
        return
    instance = self.get_instance(path)
    if (not isinstance(instance, Info)):
        return
    summary = instance.get_desc()
    self.kbbrowser.explanation.set_text(summary)
    self.kbbrowser.vuln_notebook.set_current_page(0)
    if instance.has_db_details():
        desc_markdown = instance.get_long_description()
        desc_markdown += '\n\n###    Fix    guidance\n'
        desc_markdown += instance.get_fix_guidance()
        desc_markdown += self._create_reference_list(instance)
        desc = markdown(desc_markdown)
        self.kbbrowser.description.load_html_string(desc, FILE)
    else:
        self.kbbrowser.description.load_html_string(DB_VULN_NOT_FOUND, FILE)
    if (not instance.get_id()):
        self.clear_request_response_viewer()
        return
    if (len(instance.get_id()) == 1):
        self.kbbrowser.pagesControl.deactivate()
        self.kbbrowser.page_change(0)
        self.kbbrowser.pagesControl.hide()
        self.kbbrowser.title0.hide()
        search_id = instance.get_id()[0]
        try:
            history_item = self._historyItem.read(search_id)
        except DBException:
            msg = _('The    HTTP    data    with    id    %s    is    not    inside    the    database.')
            self._show_message(_('Error'), (msg % search_id))
            self.clear_request_response_viewer()
            return
        try:
            history_item.request
            history_item.response
        except IOError as ioe:
            self._show_message(_('Error'), str(ioe))
            return
        self.kbbrowser.rrV.request.show_object(history_item.request)
        self.kbbrowser.rrV.response.show_object(history_item.response)
        severity = instance.get_severity()
        for s in instance.get_to_highlight():
            self.kbbrowser.rrV.response.highlight(s, severity)
    else:
        self.kbbrowser.pagesControl.show()
        self.kbbrowser.title0.show()
        self.kbbrowser.req_res_ids = instance.get_id()
        num_ids = len(instance.get_id())
        self.kbbrowser.pagesControl.activate(num_ids)
        self.kbbrowser.page_change(0)
    self.kbbrowser.rrV.set_sensitive(True)
