if (document.images) {

  nav7on = new Image();
  nav7on.src = "../images/nav_home_b.gif";

  nav2on = new Image();
  nav2on.src = "../images/nav_about_b.gif";

  nav3on = new Image();
  nav3on.src = "../images/nav_howitworks_b.gif";

  nav4on = new Image();
  nav4on.src = "../images/nav_faq_b.gif";

  nav5on = new Image();
  nav5on.src = "../images/nav_contact_b.gif";

  nav6on = new Image();
  nav6on.src = "../images/nav_account_b.gif";
  
  logout1on = new Image();
  logout1on.src = "../images/log_out_b.jpg";
  
 
  
  nav7off = new Image();
  nav7off.src = "../images/nav_home_a.gif";

  nav2off = new Image();
  nav2off.src = "../images/nav_about_a.gif";

  nav3off = new Image();
  nav3off.src = "../images/nav_howitworks_a.gif";

  nav4off = new Image();
  nav4off.src = "../images/nav_faq_a.gif";

  nav5off = new Image();
  nav5off.src = "../images/nav_contact_a.gif";

  nav6off = new Image();
  nav6off.src = "../images/nav_account_a.gif";  
  
  logout1off = new Image();
  logout1off.src = "../images/log_out_a.jpg";
  
  }

function changeImages() {
  if (document.images) {
    for (var i=0; i<changeImages.arguments.length; i+=2) {
      document[changeImages.arguments[i]].src = eval(changeImages.arguments[i+1] + ".src");
    }
  }
}