var i=1;
function changeImages()
{
	try 
	{
		clearTimeout(to);
	} catch (e) {}

	to = setTimeout("nextImage();", 5000);//5 sec
}

function nextImage()
{
	if(i<5)
		i=i+1;			
	else
		i=1;
		
	for(var j=1;j<6;j++){
		if(j==i)
	        document.getElementById("box"+i).style.display="";
		else
			document.getElementById("box"+j).style.display="none";
				
	}
		
	changeImages();
}