if (document.images) { 
	ton = new Image();
	ton.src = "/images/sitetwplogoon.gif";		
	toff = new Image();
	toff.src = "/images/sitetwplogo.gif";				
}
		
function roll(on){
	if (document.images) {
		if (on) {
        	document ["t"].src = ton.src;
        }
		else {
	        document ["t"].src = toff.src;		
		}
	}
}