function ShowHover(id, sel) {
  
           var item = document.getElementById('menu'+id);
           var sep_prev;
           
           sep_prev = (id==2) ? document.getElementById('menu_start') : document.getElementById('sep'+(id-2));
           sep_next = (id==10) ? document.getElementById('menu_end') : document.getElementById('sep'+(id-1));
           
           item.src= './app_themes/green/images/hovers/menu_'+id+'.jpg';
           sep_prev.src = (id==2) ? './app_themes/green/images/hovers/menu_begin.jpg' : (((id-1)==sel) ? './app_themes/green/images/hovers/menu_separator_rollover_left.jpg' : './app_themes/green/images/hovers/menu_separator_hover_left.jpg');
           sep_next.src = (id==10) ? './app_themes/green/images/hovers/menu_end.jpg' : (((id+1)==sel) ? './app_themes/green/images/hovers/menu_separator_rollover_right.jpg' : './app_themes/green/images/hovers/menu_separator_hover_right.jpg');
           
  }

  function HideHover(id, sel) {
  
           var item = document.getElementById('menu'+id);
           var sep_prev;
           
           sep_prev = (id==2) ? document.getElementById('menu_start') : document.getElementById('sep'+(id-2));
           sep_next = (id==10) ? document.getElementById('menu_end') : document.getElementById('sep'+(id-1));
           
           item.src= './app_themes/green/images/menu_'+id+'.jpg';
           sep_prev.src = (id==2) ? './app_themes/green/images/menu_begin.jpg' : (((id-1)==sel) ? './app_themes/green/images/hovers/menu_separator_hover_right.jpg' : './app_themes/green/images/menu_separator.jpg');
           sep_next.src = (id==10) ? './app_themes/green/images/menu_end.jpg' : (((id+1)==sel) ? './app_themes/green/images/hovers/menu_separator_hover_left.jpg' : './app_themes/green/images/menu_separator.jpg');
  }

  function rollout_category(id, pocet) {
  
           var kat = document.getElementById(id);
           var kat_vlakna = document.getElementById('vlakna_'+id);
           
           if (kat.className == 'kategorie_unsel') {
           
              for (i=1; i<=pocet; i++) {
              
                  document.getElementById('vlakna_kat'+i).style.display='none';
                  document.getElementById('kat'+i).className='kategorie_unsel';
              }
              
              kat.className='kategorie_sel';
              kat_vlakna.style.display='block';
           }
           else {

              kat.className='kategorie_unsel';
              kat_vlakna.style.display='none';           
           }
  }