function getObj(name) {
  var obj;
  
  if (document.getElementById) {
    obj = document.getElementById(name);
  }
  else if (document.all) {
    obj = document.all[name];
  }
  else if (document.layers) {
    obj = document.layers[name];
  }
  return obj;
}

var sideBarHeight = 890;
var sideBarYPos = 0;
var delta = 10;
var newPosition = 0;
var curPosition = 0;
var maxScrollPosition = 2700;

function floatSideBar() {
  var sideBar = getObj('buttons');

  var vDoc = (document.documentElement && document.documentElement.clientWidth)? document.documentElement : document.body;
  var scrollTop = (window.scrollY) ? window.scrollY : vDoc.scrollTop;
  
  if (scrollTop < sideBarYPos + sideBarHeight - delta)
    newPosition = sideBarYPos;
  else
    newPosition = scrollTop + delta - sideBarHeight / 2;
  
  curPosition = sideBar.offsetTop;
    
  if (newPosition == curPosition)
    return;
  
  if (newPosition + sideBarHeight > maxScrollPosition)
    newPosition = maxScrollPosition - sideBarHeight;
  
  sideBar.style.top = newPosition + 'px';
}

function initSideBar() {
  window.onscroll = floatSideBar;
}

function openInformativa() {
  var win = window.open('/informativa.html','','scrollbars=1,width=' + 600 + ', height=' + 550);

  return false;
}