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("vcard") == -1) continue;
	
	if (divs[i].getAttribute("id") != id) {		
      divs[i].style.display = "none";
    } else {
      divs[i].style.display = "block";
    }
  }
}

function prepareInternalnav() {
	
	//divs[contact].style.display = "none";
	
  if (!document.getElementsByTagName) return false;
  if (!document.getElementById) return false;
  if (!document.getElementById("content")) return false;
  
  var contNav = document.getElementById("content");
  
  var links = contNav.getElementsByTagName("a");
  
  
  for (var i=0; i<links.length; i++ ) {
	//alert(String(links[i].getAttribute("href").split("#")[1]));
	  
    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);