function div_pokazi(divname)
{
   /*
   var mydiv = document.getElementById(divname);
   mydiv.style.visibility="";
   mydiv.style.display="";
   */
   if (mydiv == null)
   {
      alert("Sorry can't find your div");
   }

   document.getElementById(divname).style.display = 'block';
   alert (divname);
}
function div_skrij(divname)
{
   /*
   var mydiv = document.getElementById(divname);
   mydiv.style.visibility="";
   mydiv.style.display="none";
   */
   if (mydiv == null)
   {
      alert("Sorry can't find your div");
   }

   document.getElementById(divname).style.display = 'none';
   alert ("yes");
}