function close_popup() {
	document.getElementById('popup').innerHTML="";
	document.getElementById('popup').style.display="none";
	document.getElementById('cover').style.display="none";
}
function open_popup( uri, wi, he) {
		var he = (he == null) ? 500 : he;
		var wi = (wi == null) ? 680 : wi;
		document.getElementById('cover').style.display="block";
		document.getElementById('popup').style.display="block";
		offset=window.pageYOffset||document.body.scrollTop||document.documentElement.scrollTop;
		document.getElementById('popup').style.top=40+offset+'px';
		document.getElementById('popup').style.width=wi+'px';
		document.getElementById('popup').style.left=(screen.width-wi)/2+'px';
		document.getElementById('popup').innerHTML="<iframe src='"+uri+"' width='100%' height='"+he+"' frameborder='0' id='"+Math.floor(Math.random()*10001)+"'></iframe>";
}