function radio(checkboxName)
   {
      if(checkboxName == 'none')
         {
            document.getElementById('certifikat').style.display = 'none';
         }
      else document.getElementById('certifikat').style.display = 'block';
   }

function hiddenbox(checkboxName,hiddenName)
   {
      if(document.getElementById(checkboxName).checked)
         {
            document.getElementById(hiddenName).style.display = 'block';
         }
      else document.getElementById(hiddenName).style.display = 'none';
   }