addLoadEvent(init);


function init()
{
   initImages('topnav');
   initImages('tabs');
}

function initImages(divId)
{
   if (document.getElementById)
      var x = document.getElementById(divId).getElementsByTagName('IMG');
   else if (document.all)
      var x = document.all[divId].all.tags('IMG');
   else return;
   var preloads = new Object();
   for (var i=0;i<x.length;i++)
   {
      if (-1 == x[i].getAttribute('src').indexOf('images/nav'))
         continue;
      if (null == x[i].parentNode.getAttribute('href'))
         continue;
      if (-1 != x[i].getAttribute('src').indexOf('_Select'))
         continue;

      var extension = 'gif';
      if (-1 != x[i].getAttribute('src').indexOf('jpg'))
         extension = 'jpg';

      preloads['ni'+x[i].id] = new Image;
      preloads['ni'+x[i].id].src = 'images/nav/' + x[i].getAttribute('id') +  '_Norm.' + extension;
      preloads['oi'+x[i].id] = new Image;
      preloads['oi'+x[i].id].src = 'images/nav/' + x[i].getAttribute('id') + '_Over.' + extension;
      x[i].onmouseover = function () {this.src=preloads['oi'+this.id].src;}
      x[i].onmouseout = function ()  {this.src=preloads['ni'+this.id].src;}
   }
}


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