preload_image ("/images/nav_home_on.png");
preload_image ("/images/nav_home_hover.png");
preload_image ("/images/nav_home_off.png");
preload_image ("/images/nav_books_on.png");
preload_image ("/images/nav_books_hover.png");
preload_image ("/images/nav_books_off.png");
preload_image ("/images/nav_faq_on.png");
preload_image ("/images/nav_faq_hover.png");
preload_image ("/images/nav_faq_off.png");
preload_image ("/images/nav_blog_on.png");
preload_image ("/images/nav_blog_hover.png");
preload_image ("/images/nav_blog_off.png");
preload_image ("/images/nav_support_on.png");
preload_image ("/images/nav_support_hover.png");
preload_image ("/images/nav_support_off.png");

function preload_image (image_src) {
	jQuery ('<img src="' + image_src + '" />');
}