// Preload Nav Images
var home_ov = new Image();
home_ov.src = '/images/cart/buttons/home_ov.gif';

// Preload Invoice Images
var back_ov = new Image();
back_ov.src = '/images/cart/buttons/back_ov.gif';

var print_ov = new Image();
print_ov.src = '/images/cart/buttons/print_ov.gif';

var submit_ov = new Image();
submit_ov.src = '/images/cart/buttons/submit_ov.gif';