function checkLength(element, maxLength){
  if (element.value.length > maxLength)
     element.value = element.value.substr(0, maxLength);
  var el = document.getElementById(element.id+'_notify');
  if (el)
    el.innerHTML = (maxLength-element.value.length) + ' ' + characters;
}

function checkPass(el1, el2, elNotify){
  var el;
  if (el = document.getElementById(elNotify))
      if (el1.value == el2.value)
         el.innerHTML = 'Ok';
        else
            el.innerHTML = 'Zadané heslá sa nezhodujú';

}