function footer() {
	document.writeln('');
}

function banner() {
	document.writeln('<embed flashvars=\"link=#\" src=\"img/banner/header.swf\" type=\"application/x-shockwave-flash\" width=\"480\" height=\"80\" />');
}

function headbanner() {
	document.writeln('<embed flashvars=\"link=#\" src=\"img/banner/head.swf\" type=\"application/x-shockwave-flash\" width=\"616\" height=\"80\" />');
}

function left(){
	document.writeln('');
}

function right(){
}
function hien( id )
{
	var divs = document.getElementById("thucdon").getElementsByTagName("div");
	for(i = 0; i < divs.length; i++){
	    divs[i].style.display = "none";
	}
	document.getElementById(id).style.display = "block";
}
function bookmarksite(title, url){
	if (document.all)
	window.external.AddFavorite(url, title);
	else if (window.sidebar)
	window.sidebar.addPanel(title, url, "")
}