// JavaScript Document
var index=1;
function hinh(i)
{
	index=i;
	document.getElementById("hinh_banner").src="images/layout/banner"+i+".png";
}

function hinhtruoc()
{
	index--;
	if(index<1)
		index=3;
	document.getElementById("hinh_banner").src="images/layout/banner"+index+".png";
}
function hinhsau()
{
	index++;
	if(index>3)
		index=1;
	document.getElementById("hinh_banner").src="images/layout/banner"+index+".png";
}