function startup(){
  preload()
  highlight_buttons()
  
}

function preload(){

  if (document.images)
  {
    preload_image_object = new Image();
    // set image url
    image_url = new Array();
    image_url[0] = "http://xiling.at/img/menu/hnavkollektionen_over.png";
    image_url[1] = "./img/menu/hnavnews_over.png";
    image_url[3] = "./img/menu/hnavseide_over.png";
    image_url[4] = "./img/menu/hnavkontakt_over.png";
    image_url[5] = "./img/menu/hnavlinks_over.png";
    image_url[6] = "./img/menu/hnavshop_over.png";
    image_url[7] = "./img/menu/subnavbabies_over.png";
    image_url[8] = "./img/menu/subnavfrauen_over.png";
    image_url[9] = "./img/menu/subnavmaenner_over.png";
    image_url[10] = "./img/menu/subnavjugendliche_over.png";
    image_url[11] = "./img/menu/subnavphilosophie_over.png";
    image_url[12] = "./img/menu/subnavqualitaet_over.png";
    image_url[13] = "./img/menu/subnaveigenschaften_over.png";
    image_url[14] = "./img/menu/subnavpflege_over.png";
    image_url[15] = "./img/menu/subnavoekologie_over.png";
    image_url[16] = "./img/start/001a.jpg";
    image_url[17] = "./img/start/001b.jpg";
    image_url[18] = "./img/start/002a.jpg";
    image_url[19] = "./img/start/002b.jpg";
    image_url[20] = "./img/start/003a.jpg";
    image_url[21] = "./img/start/003b.jpg";
    image_url[22] = "./img/start/004a.jpg";
    image_url[23] = "./img/start/004b.jpg";
    image_url[24] = "./img/start/005a.jpg";
    image_url[25] = "./img/start/005b.jpg";
    image_url[26] = "./img/start/006a.jpg";
    image_url[27] = "./img/start/006b.jpg";
    image_url[28] = "./img/start/007a.jpg";
    image_url[29] = "./img/start/007b.jpg";
    image_url[30] = "./img/start/008a.jpg";
    image_url[31] = "./img/start/008b.jpg";
    image_url[32] = "./img/start/009a.jpg";
    image_url[33] = "./img/start/009b.jpg";
    image_url[34] = "./img/start/010a.jpg";
    image_url[35] = "./img/start/010b.jpg";
  
     var i = 0;
     for(i=0; i<=35; i++) 
       preload_image_object.src = image_url[i];
  }
}

function highlight_buttons(){
    if(nav != "bt_"){
        document[nav].src = document[nav].src.replace(png,pngover)
    }
    if(subnav != "bt_"){
        document[subnav].src = document[subnav].src.replace(png,pngover)
    }
}