if(document.images) {
  var start_off             = new Image(); start_off.src             = "./icons/icon_start_2.gif";
  var start_on              = new Image(); start_on .src             = "./icons/icon_start_3.gif";
  var neues_off             = new Image(); neues_off.src             = "./icons/icon_neues_2.gif";
  var neues_on              = new Image(); neues_on .src             = "./icons/icon_neues_3.gif";
  var gaestebuch_off        = new Image(); gaestebuch_off.src        = "./icons/icon_gaestebuch_2.gif";
  var gaestebuch_on         = new Image(); gaestebuch_on .src        = "./icons/icon_gaestebuch_3.gif";
  var impressum_off         = new Image(); impressum_off.src         = "./icons/icon_impressum_2.gif";
  var impressum_on          = new Image(); impressum_on .src         = "./icons/icon_impressum_3.gif";
  var links_off             = new Image(); links_off.src             = "./icons/icon_links_2.gif";
  var links_on              = new Image(); links_on .src             = "./icons/icon_links_3.gif";

  var sonette_off           = new Image(); sonette_off.src           = "./icons/icon_sonette_2.gif";
  var sonette_on            = new Image(); sonette_on .src           = "./icons/icon_sonette_3.gif";
  var balladellen_off       = new Image(); balladellen_off.src       = "./icons/icon_balladellen_2.gif";
  var balladellen_on        = new Image(); balladellen_on .src       = "./icons/icon_balladellen_3.gif";
  var vieh_off              = new Image(); vieh_off.src              = "./icons/icon_vieh_2.gif";
  var vieh_on               = new Image(); vieh_on .src              = "./icons/icon_vieh_3.gif";
  var befindlichkeiten_off  = new Image(); befindlichkeiten_off.src  = "./icons/icon_befindlichkeiten_2.gif";
  var befindlichkeiten_on   = new Image(); befindlichkeiten_on .src  = "./icons/icon_befindlichkeiten_3.gif";
  var liebesgedichte_off    = new Image(); liebesgedichte_off.src    = "./icons/icon_liebesgedichte_2.gif";
  var liebesgedichte_on     = new Image(); liebesgedichte_on .src    = "./icons/icon_liebesgedichte_3.gif";
  var animalien_off         = new Image(); animalien_off.src         = "./icons/icon_animalien_2.gif";
  var animalien_on          = new Image(); animalien_on .src         = "./icons/icon_animalien_3.gif";
  var intl_off              = new Image(); intl_off.src              = "./icons/icon_intl_2.gif";
  var intl_on               = new Image(); intl_on .src              = "./icons/icon_intl_3.gif";
  var bildkritiken_off      = new Image(); bildkritiken_off.src      = "./icons/icon_bildkritiken_2.gif";
  var bildkritiken_on       = new Image(); bildkritiken_on .src      = "./icons/icon_bildkritiken_3.gif";
  var erzaehlungen_off      = new Image(); erzaehlungen_off.src      = "./icons/icon_erzaehlungen_2.gif";
  var erzaehlungen_on       = new Image(); erzaehlungen_on .src      = "./icons/icon_erzaehlungen_3.gif";
  var lyrikpuzzle_off       = new Image(); lyrikpuzzle_off.src       = "./icons/icon_lyrikpuzzle_2.gif";
  var lyrikpuzzle_on        = new Image(); lyrikpuzzle_on .src       = "./icons/icon_lyrikpuzzle_3.gif";
  var index_off             = new Image(); index_off.src             = "./icons/icon_index_2.gif";
  var index_on              = new Image(); index_on .src             = "./icons/icon_index_3.gif";
}
function act(imgName) {
  if (document.images){
    document[imgName].src = eval(imgName + '_on.src');
  }
}
function deact(imgName) {
  if (document.images){
    document[imgName].src = eval(imgName + '_off.src');
  }
}