function show_hotspot (key){
    
    var hotul=document.getElementById("hotspotul");
   var hotspotlist=hotul.getElementsByTagName("li");

     var ul_menu=document.getElementById("hotspot_menu");
    var menuitems=ul_menu.getElementsByTagName("li");

    

      for (var i =0; i < hotspotlist.length; i++){
          
           var this_hotspot = hotspotlist[i];
           var this_menuitem = menuitems[i];
   
           var baseclass;
           var this_class= this_menuitem.className;
           
           if (this_class.match (/^([^_]*)_/)){
               baseclass = RegExp.$1;
           }           

           if (key == this_hotspot.id){
                this_hotspot.style.display = '';
                 this_menuitem.className = baseclass + '_active' ;            
           }
          else{
                 this_hotspot.style.display = 'none';
                  this_menuitem.className= baseclass + '_passive';
          }
       }
}