if(document.images) {
  
	var kisson = new Image();  
	var kissoff = new Image();
	var whoon = new Image();
	var whooff = new Image();
	var nixonon = new Image();
	var nixonoff = new Image();
	
	kisson.src = "images/sf_kiss_on.gif";  
	kissoff.src = "images/sf_kiss_off.gif";
	whoon.src = "images/sf_who_on.gif";  
	whooff.src = "images/sf_who_off.gif";
	nixonon.src = "images/sf_visit_on.gif";  
	nixonoff.src = "images/sf_visit_off.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');
	}
}