function changeDiv(i,maxi){
	var previous=i-1;
	if(i==1){
		previous=maxi;
	}
	document.getElementById(previous).style.visibility='hidden';
	document.getElementById(i).style.visibility='visible';
}

function rotate(i,maxi){
	var next=i+1;
	if(i==maxi){
		next=1;
	}
	
	changeDiv(i,maxi);
	setTimeout('rotate('+next+','+maxi+')',6000);
}