function zmenZalozku(div) {
   if (document.getElementById('specifikace')) {
      var option = ['specifikace','manualy'];
      for(var i=0; i<option.length; i++) { 
         obj=document.getElementById(option[i]);
         obj.className = (option[i] == div)? "ukaz" : "skryj";
         
         obj_a=document.getElementById(option[i]+'-a');
         obj_a.className = (option[i] == div)? "active" : "";
      }
   }
}