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) {
h_home_over = newImage("images/header/h_home_over.jpg");
h_boxes_over = newImage("images/header/h_boxes_over.jpg");
h_displays_over = newImage("images/header/h_displays_over.jpg");
h_about_over = newImage("images/header/h_about_over.jpg");
h_contact_over = newImage("images/header/h_contact_over.jpg");
preloadFlag = true;
}
}