if(document.images) {
  
	var playlon = new Image();  
	var playloff = new Image();
	var articleon = new Image();
	var articleoff = new Image();
	var interviewon = new Image();
	var interviewoff = new Image();
	
	playloff.src = "images/sf_play_off.gif"
	playlon.src = "images/sf_play_on.gif"
	articleoff.src = "images/sf_article_off.gif"
	articleon.src = "images/sf_article_on.gif"
	interviewoff.src = "images/sf_interview_off.gif"
	interviewon.src = "images/sf_interview_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');
	}
}