if (document.images) {
     nav_aboutch1 = new Image
     nav_aboutch2 = new Image

     nav_aboutch1.src = 'images/nav/aboutch_link.gif'
     nav_aboutch2.src = 'images/nav/aboutch_active.gif'
 }
 
 if (document.images) {
     nav_whichservice1 = new Image
     nav_whichservice2 = new Image

     nav_whichservice1.src = 'images/nav/whichservices_link.gif'
     nav_whichservice2.src = 'images/nav/whichservices_active.gif'
 }
 
  if (document.images) {
     nav_contactus1 = new Image
     nav_contactus2 = new Image

     nav_contactus1.src = 'images/nav/contactus_link.gif'
     nav_contactus2.src = 'images/nav/contactus_active.gif'
 }