function newImage(arg) {

     if (document.images) {

          rslt = new Image();

          rslt.src = arg;

          return rslt;
     }
}

function changeImages() {

     if (document.images && (preloadFlag == true)) {

          for (var i=0; i<changeImages.arguments.length; i+=2) {

               document[changeImages.arguments[i]].src = changeImages.arguments[i+1];
         }
     }
}

var preloadFlag = false;

function preloadImages() {

     if (document.images) {

          homeover = newImage("i/homeover.gif");
          home = newImage("i/home.gif");

          aboutover = newImage("i/aboutover.gif");
          about = newImage("i/about.gif");

          productover = newImage("i/productover.gif");
          product = newImage("i/product.gif");

          servicesover = newImage("i/servicesover.gif");
          services = newImage("i/services.gif");

          contactover = newImage("i/contactover.gif");
          contact = newImage("i/contact.gif");

          preloadFlag = true;
     }
}