/** Based on code from Jeremy Keith's website: 
 * http://domscripting.com/domsters/about.html
 */

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

function showSection(id) {
  var divs = document.getElementsByTagName("div");
  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 prepareInternalnav() {
  if (!document.getElementsByTagName) return false;
  if (!document.getElementById) return false;
  if (!document.getElementById("internalnav")) return false;
  var nav = document.getElementById("internalnav");
  var links = nav.getElementsByTagName("a");
  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);
addLoadEvent(start);