# CREATE TABLE b_struct (
#   l int(32) unsigned NOT NULL default '0',
#   r int(32) unsigned NOT NULL default '0',
#   id int(32) unsigned NOT NULL auto_increment,
# es folgen die Metadaten:
#   num int(10) unsigned NOT NULL default '0', # laufende Nummer
#   nick varchar(120) NOT NULL default '',     # Name des Item
#   level int(32) unsigned NOT NULL default '0',# Schachtelungstiefe
#   groupid int(32) unsigned NOT NULL default '0',# Übergeordnetes Item
## es folgen die verwalteten Daten, hier ausgelassen
#   PRIMARY KEY  (id),
#   KEY nick (nick)
# ) TYPE=MyISAM;
#---------------------------------------------------------------------
#    Funktionen
#
#   sub move_up_by_id
#   sub move_down_by_id
#    sub _move_item_extract
#    sub _move_item_add
#    sub _move_item_insert
#   
#   sub item_insert
#   sub item_add
#   sub item_delete
#   sub extract_to_newstruct
#   sub get_path
#   sub get_inside_item
#   sub get_groups_inside_item
#   sub get_all_inside_item
#   sub get_same_group
#   sub _refresh_struct
#   sub _set_level()
#
#----------------------------------------------------------------------