//couple of global arrays
var nav_items = document.getElementsByTagName("a");
var page_items = document.getElementsByName("pageItem");
  

//highlights clicked sub-item and makes sure rest are de-selected
function currentNavItem() {
  for (var i=0; i < nav_items.length; i++) {
    if (nav_items[i].className.match("nested_nav_item")){
      nav_items[i].onclick = function() {
        displayPageItem(this.id);
        deselectNestedNavItems();
        this.className = "nested_nav_item selected";
        }
      }
    }
}

//deselects all nested_nav_item elements (called in currentNavItem above)
function deselectNestedNavItems() {
  for (var i=0; i < nav_items.length; i++) {
      if (nav_items[i].className.match("nested_nav_item")){
        nav_items[i].className = "nested_nav_item";
        }
      }
    }
    

//displays page_item corresponding to the clicked nested_nav_item
function displayPageItem(item_class_name) {
  for (var i=0; i < page_items.length; i++) {
      if (page_items[i].className.match(item_class_name)){
        page_items[i].style.display = "block";
        }
      else {
          page_items[i].style.display = "none";
        }
      }
    }

//put it all together
function init() {
  currentNavItem ();
  if (document.getElementsByName("pageItem")[0]){
    document.getElementsByName('pageItem')[0].style.display='block';
  }
}


window.onload = init;