if(document.images) {
  
	var caron = new Image();  
	var caroff = new Image();
	var decoon = new Image();
	var decooff = new Image();
	var postcardon = new Image();
	var postcardoff = new Image();
	var todayon = new Image();
	var todayoff = new Image();
	
	caroff.src = "images/sf_car_off.gif"
	caron.src = "images/sf_car_on.gif"
	decooff.src = "images/sf_deco_off.gif"
	decoon.src = "images/sf_deco_on.gif"
	postcardoff.src = "images/sf_postcard_off.gif"
	postcardon.src = "images/sf_postcard_on.gif"
	todayoff.src = "images/sf_today_off.gif"
	todayon.src = "images/sf_today_on.gif"
}


function off(imgName) {
	if(document.images) {
	document[imgName].src = eval(imgName + 'off.src');
	}
}

function on(imgName) {
	if(document.images) {
	document[imgName].src = eval(imgName + 'on.src');
	}
}