function externalLinks() {
 if (!document.getElementsByTagName) return;
 var anchors = document.getElementsByTagName("a");
 for (var i=0; i<anchors.length; i++) {
   var anchor = anchors[i];
   if (anchor.getAttribute("href") &&
       anchor.getAttribute("rel") == "external")
     anchor.target = "_blank";
 }
}
window.onload = externalLinks;




if (document.images) 
{
   img1 = new Image();
   img2 = new Image();
   img3 = new Image();
   img4 = new Image();
   img1.src = "images/mainmenu_who2.gif";
   img2.src = "images/mainmenu_what2.gif";
   img3.src = "images/mainmenu_learning2.gif";
   img4.src = "images/mainmenu_contact2.gif";
}