function addLoadEvent(func) {
  var oldonload = window.onload;
  if (typeof window.onload != 'function') {
    window.onload = func;
  } else {
    window.onload = function() {
      oldonload();
      func();
    }
  }
}

function insertAfter(newElement,targetElement) {
  var parent = targetElement.parentNode;
  if (parent.lastChild == targetElement) {
    parent.appendChild(newElement);
  } else {
    parent.insertBefore(newElement,targetElement.nextSibling);
  }
}

function addClass(element,value) {
  if (!element.className) {
    element.className = value;
  } else {
    newClassName = element.className;
    newClassName+= " ";
    newClassName+= value;
    element.className = newClassName;
  }
}

function highlightPage() {
  if (!document.getElementsByTagName) return false;
  if (!document.getElementById) return false;
  if (!document.getElementById("nav")) return false;
	var section = document.body.getAttribute("id");
	var nav = document.getElementById("nav");
  var links = nav.getElementsByTagName("a");
  for (var i=0; i<links.length; i++) {
    var linktext = links[i].lastChild.nodeValue.toLowerCase();
    if (linktext == section) {
      links[i].className = "active";
    }
  }
}

addLoadEvent(highlightPage);