[sana]

Не скопировала...

// Menu

function expand_click() {
  var expand = next(this),
      clsName = expand.className;

  expand.className = 'submenu' + (clsName.indexOf("hidden") >=0 ? '' : ' hidden');
}

function initExpand() {
  var expandera = document.getElementsByTagName("h4"), elem;
  for(var i = 0; i < expandera.length ;i++) {
    elem = expandera[i];
    if(elem.className == "expandera") {
      elem.onclick = expand_click;
      next(elem).className = "submenu hidden";
    }
  }
}


window.onload = initExpand;


function next(elem) {
do {
elem = elem.nextSibling;
} while (elem && elem.nodeType != 1);
return elem;
}