first = 0;
   bildergalerie_up_started = 0;
   bildergalerie_up_interval = 0;
   bildergalerie_up_stopped = 0;
   bildergalerie_down_started = 0;
   bildergalerie_down_interval = 0;
   bildergalerie_down_stopped = 0;
   waittime = 800;

   function bildergalerie_up_start() {
      if(bildergalerie_up_started == 0) {
          bildergalerie_up_started = 1;
          if(bildergalerie_up_stopped == 0) {
              bildergalerie_up();
          }
          bildergalerie_up_interval = window.setInterval("bildergalerie_up()", waittime);
      }
   }
   
   function bildergalerie_up_stop() {
      window.clearInterval(bildergalerie_up_interval);
      bildergalerie_up_started = 0;
      bildergalerie_up_stopped = 1;
      window.setTimeout("bildergalerie_up_stopped = 0;", waittime);
   }
   
   function bildergalerie_down_start(maximum_down) {
      if(bildergalerie_down_started == 0) {
          bildergalerie_down_started = 1;
          if(bildergalerie_down_stopped == 0) {
              bildergalerie_down(maximum_down);
          }
          bildergalerie_down_interval = window.setInterval("bildergalerie_down("+maximum_down+")", waittime);
      }
   }
   
   function bildergalerie_down_stop(maximum_down) {
      window.clearInterval(bildergalerie_down_interval);
      bildergalerie_down_started = 0;
      bildergalerie_down_stopped = 1;
      window.setTimeout("bildergalerie_down_stopped = 0;", waittime);
   }
   
   function bildergalerie_up() {
      if(first > 0 && bildergalerie_up_started == 1) {
         first--;
         document.getElementById("bildergalerie_image_"+first).style.display = "";
         document.getElementById("bildergalerie_image_"+(first+4)).style.display = "none";

         if(first == 0) {
            document.getElementById("bildergalerie_up").style.display = "none";
         }

         if(document.getElementById("bildergalerie_down").style.display == "none") {
            document.getElementById("bildergalerie_down").style.display = "";
         }
      }
   }

   function bildergalerie_down(max_num) {
      if((max_num-4) > first && bildergalerie_down_started == 1) {
         document.getElementById("bildergalerie_image_"+first).style.display = "none";
         document.getElementById("bildergalerie_image_"+(first+4)).style.display = "";
         first++;
         document.getElementById("bildergalerie_up").style.display = "";

         if((max_num-4) == first) {
            document.getElementById("bildergalerie_down").style.display = "none";
         }
      }
   }

   function bildergalerie_show( bild ) {
      document.getElementById('bildergalerie_contentpicture').style.backgroundImage = 'url('+bild+')';
   }