function showSection(id) {
  var divs = document.getElementsByTagName("dd");
  for (var i=0; i<divs.length; i++ ) {
    if (divs[i].className.indexOf("section") == -1) continue;
    if (divs[i].getAttribute("id") != id) {
      divs[i].style.display = "none";
    } else {
      divs[i].style.display = "block";
    }
  }
}

function getElementsByClassName(oElm, strTagName, strClassName){
    var arrElements = (strTagName == "*" && oElm.all)? oElm.all : oElm.getElementsByTagName(strTagName);
    var arrReturnElements = new Array();
    strClassName = strClassName.replace(/\-/g, "\\-");
    var oRegExp = new RegExp("(^|\\s)" + strClassName + "(\\s|$)");
    var oElement;
    for(var i=0; i<arrElements.length; i++){
        oElement = arrElements[i];      
        if(oRegExp.test(oElement.className)){
            arrReturnElements.push(oElement);
        }   
    }
    return (arrReturnElements)
}

function prepareInternalnav() {
  if (!document.getElementsByTagName) return false;
  if (!document.getElementById) return false;
  if (!document.getElementById("section-list")) return false;
  var nav = document.getElementById("section-list");
  var links = getElementsByClassName(nav, "a", "head-link");
  if (links.length > 1){
	  for (var i=0; i<links.length; i++ ) {
	    var sectionId = links[i].getAttribute("href").split("#")[1];
	    if (!document.getElementById(sectionId)) continue;	    
	    document.getElementById(sectionId).style.display = "none";
	    links[i].destination = sectionId;
	    links[i].onclick = function() {
	      showSection(this.destination);
	      return false;
	    }
	  }
  }
}

addLoadEvent(prepareInternalnav);