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();
   img5 = new Image();
   img6 = new Image();
   img7 = new Image();


   img1.src = "images/nav_home_on.gif";
   img2.src = "images/nav_about_on.gif";
   img3.src = "images/nav_services_on.gif";
   img4.src = "images/nav_bb_on.gif";
   img5.src = "images/nav_patient_on.gif";
   img6.src = "images/nav_products_on.gif";
   img7.src = "images/nav_contact_on.gif"; 
}