if (document.images)  {
  
   			 about_on = new Image;
   			 about_off = new Image;
   			 about_ch_on = new Image;
   			 about_ch_off = new Image;
   			 about_clients_on = new Image;
   			 about_clients_off = new Image;
   			 about_careers_on = new Image;
   			 about_careers_off = new Image;
   			 about_mgmnt_on = new Image;
   			 about_mgmnt_off = new Image;
   			 about_events_on = new Image;
   			 about_events_off = new Image;
   			 dentistat_on = new Image;
   			 dentistat_off = new Image;
   			 dent_rel_on = new Image;
   			 dent_rel_off = new Image;
   			 dent_val_on = new Image;
   			 dent_val_off = new Image;
   			 dent_faq_on = new Image;
   			 dent_faq_off = new Image;
   			 services_on = new Image;
   			 services_off = new Image;
   			 services_um_on = new Image;
   			 services_web_off = new Image;
   			 services_web_on = new Image;
   			 services_um_off = new Image;
   			 services_ap_on = new Image;
   			 services_ap_off = new Image;
   			 services_recred_off = new Image;
   			 services_recred_on = new Image;
   			 services_pg_off = new Image;
   			 services_pg_on = new Image;
   			 services_clnt_off = new Image;
   			 services_clnt_on = new Image;
   			 services_is_off = new Image;
   			 services_is_on = new Image;
   			 resources_off = new Image;
   			 resources_on = new Image;
   			 contact_off = new Image;   			 
   			 contact_on = new Image;
   			 ecom_off = new Image;
   			 home_on = new Image;
   			 home_off = new Image;
    		     login_on = new Image;
   			 login_off = new Image;
    		     provider_on = new Image;
   			 provider_off = new Image;


   			 about_on.src = "images/nav/den_nav_on_about.gif";
   			 about_off.src = "images/nav/den_nav_off_about.gif";
   			 about_ch_on.src = "images/nav/den_nav_on_about_ch.gif";
   			 about_ch_off.src = "images/nav/den_nav_off_about_ch.gif";
   			 about_clients_on.src = "images/nav/den_nav_on_about_cl.gif";
   			 about_clients_off.src = "images/nav/den_nav_off_about_cl.gif";
   			 about_careers_on.src = "images/nav/den_nav_on_about_careers.gif";
   			 about_careers_off.src = "images/nav/den_nav_off_about_careers.gif";
   			 about_mgmnt_on.src = "images/nav/den_nav_on_about_mgmnt.gif";
   			 about_mgmnt_off.src = "images/nav/den_nav_off_about_mgmnt.gif";
   			 about_events_on.src = "images/nav/den_nav_on_about_pe.gif";
   			 about_events_off.src = "images/nav/den_nav_off_about_pe.gif";
   			 dentistat_on.src = "images/nav/den_nav_on_dentad.gif";
   			 dentistat_off.src = "images/nav/den_nav_off_dentad.gif";
   			 dent_rel_on.src = "images/nav/den_nav_on_dentad_rel.gif";
   			 dent_rel_off.src = "images/nav/den_nav_off_dentad_rel.gif";
   			 dent_val_on.src = "images/nav/den_nav_on_dentad_val.gif";
   			 dent_val_off.src = "images/nav/den_nav_off_dentad_val.gif";
   			 dent_faq_on.src = "images/nav/den_nav_on_dentad_faq.gif";
   			 dent_faq_off.src = "images/nav/den_nav_off_dentad_faq.gif";
   			 services_on.src = "images/nav/den_nav_on_svcs.gif";
   			 services_off.src = "images/nav/den_nav_off_svcs.gif";
   			 services_um_on.src = "images/nav/den_nav_on_svcs_um.gif";
   			 services_um_off.src = "images/nav/den_nav_off_svcs_um.gif";
             services_web_on.src = "images/nav/den_nav_on_svcs_web.gif";
   			 services_web_off.src = "images/nav/den_nav_off_svcs_web.gif";
   			 services_ap_on.src = "images/nav/den_nav_on_svcs_app.gif";
   			 services_ap_off.src = "images/nav/den_nav_off_svcs_app.gif";
   			 services_recred_on.src = "images/nav/den_nav_on_svcs_recr.gif";
   			 services_recred_off.src = "images/nav/den_nav_off_svcs_recr.gif";
   			 services_pg_on.src = "images/nav/den_nav_on_svcs_pg.gif";
   			 services_pg_off.src = "images/nav/den_nav_off_svcs_pg.gif";
   			 services_clnt_on.src = "images/nav/den_nav_on_svcs_clnt.gif";
   			 services_clnt_off.src = "images/nav/den_nav_off_svcs_clnt.gif";
   			 services_is_on.src = "images/nav/den_nav_on_svcs_is.gif";
   			 services_is_off.src = "images/nav/den_nav_off_svcs_is.gif";
   			 resources_on.src = "images/nav/den_nav_on_rsrcs.gif";
   			 resources_off.src = "images/nav/den_nav_off_rsrcs.gif";
   			 contact_on.src = "images/nav/den_nav_on_contact.gif";   			 
   			 contact_off.src = "images/nav/den_nav_off_contact.gif";

   			 home_on.src = "images/nav/den_nav_on_hm.gif";
   			 home_off.src = "images/nav/den_nav_off_hm.gif";
    		     login_on.src = "images/nav/den_nav_on_client.gif";
   			 login_off.src = "images/nav/den_nav_off_client.gif";
    		     provider_on.src = "images/nav/den_nav_on_provider.gif";
   			 provider_off.src = "images/nav/den_nav_off_provider.gif";

   			 }
  
		function chgImg(imgField,newImg) {
       	
       	 if (document.images) {
           	document[imgField].src = eval(newImg + ".src")
            
         }
      }