// JavaScript Document

// DropDownMenu by Miha Hribar
// http://hribar.info

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



function prepareMenu() {
  // first lets make sure the browser understands the DOM methods we will be using
  if (!document.getElementsByTagName) return false;
  if (!document.getElementById) return false;

  // lets make sure the element exists
  if (!document.getElementById("top_menu")) return false;
  var menu = document.getElementById("top_menu");

  // for each of the li on the root level check if the element has any children
  // if so append a function that makes the element appear when hovered over
  var root_li = menu.getElementsByTagName("li");
  for (var i = 0; i < root_li.length; i++) {
    var li = root_li[i];
    // search for children
    var child_ul = li.getElementsByTagName("ul");
    if (child_ul.length >= 1) {
      // we have children - append hover function to the parent
        li.onmouseover = function () {
        if (!this.getElementsByTagName("ul")) return false;
        var ul = this.getElementsByTagName("ul");
        
        ul[0].style.display = "block";
        return true;
      }
        li.onmouseout = function () {
        if (!this.getElementsByTagName("ul")) return false;
        var ul = this.getElementsByTagName("ul");
        ul[0].style.display = 'none';
        return true;
      }
    }
  }

  return true;
}


addLoadEvent(prepareMenu);