function AttachEvents() {
  var YearsDiv = document.getElementById("Years");
  for (var i=0; i<YearsDiv.childNodes.length; i++ ) {
    elm = YearsDiv.childNodes[i];
    if (elm.tagName != "LI") continue;
    if (elm.getElementsByTagName("p") != null) {
      AddEvent(elm.getElementsByTagName("p")[0],"mouseover", DecadeMouseOver);
    }
    
  }
}

function DecadeMouseOver(evt) {

  var YearsDiv = document.getElementById("Years");
  for (var i=0; i<YearsDiv.childNodes.length; i++ ) {
    elm = YearsDiv.childNodes[i];
    if (elm.tagName != "LI") continue;
    elm.className = "";
    uls = elm.getElementsByTagName("ul");
    for (var j=0; j< uls.length; j++) {
      uls[j].style.display = "none";
    }
  }
  var elm = (evt.target) ? evt.target : evt.srcElement;
  elm = elm.parentNode;
  DisplayDecade(elm);
}

function DisplayDecade(elm) {

  elm.className = "Selected";
  uls = elm.getElementsByTagName("ul");
  for (var i=0; i< uls.length; i++) {
    uls[i].style.display = "inline";

    //margin = -3 * uls[i].getElementsByTagName("li").length/2;
    //uls[i].style.marginLeft = margin + "ex";

  }
}

function ShowVideo(id) {
  var style = document.getElementById(id).style;
  style.display = style.display == 'block' ? 'none' : 'block';
  
}