if (document.images) {
	home1 = new Image; home1.src = "images/nav_home_a.gif"
	home0 = new Image; home0.src = "images/nav_home_b.gif"
	tour1 = new Image; tour1.src = "images/nav_tour_a.gif"
	tour0 = new Image; tour0.src = "images/nav_tour_b.gif"
    history1 = new Image; history1.src = "images/nav_history_a.gif"
	history0 = new Image; history0.src = "images/nav_history_b.gif"
	order1 = new Image; order1.src = "images/nav_order_a.gif"
	order0 = new Image; order0.src = "images/nav_order_b.gif"
	contact1 = new Image; contact1.src = "images/nav_contact_a.gif"
	contact0 = new Image; contact0.src = "images/nav_contact_b.gif"

}
else {
 home1 = ""
	home0 = ""
	document.home.src = ""
	document.tour.src = ""
	document.history.src = ""
	document.order.src = ""
	document.contact.src = ""
}