function getWidth()
{
	return window.innerWidth ? window.innerWidth : /* For non-IE */
	document.documentElement ? document.documentElement.clientWidth : /* IE 6+ (Standards Compilant Mode) */
	document.body ? document.body.clientWidth : /* IE 4 Compatible */
	window.screen.width; /* Others (It is not browser window size, but screen size) */
}

function getHeight()
{
	return window.innerHeight ? window.innerHeight : /* For non-IE */
	document.documentElement ? document.documentElement.clientHeight : /* IE 6+ (Standards Compilant Mode) */
	document.body ? document.body.clientHeight : /* IE 4 Compatible */
	window.screen.height; /* Others (It is not browser window size, but screen size) */
}

function PopUp(id) {
	if(document.getElementById(id).attributes["class"].value == "popup") {
		document.getElementById(id).style.left = ((getWidth().toString()-1000)/2)+"px";
		
		document.getElementById(id).attributes["class"].value = "popup_mostra";
	} else {
		document.getElementById(id).attributes["class"].value = "popup";
	}
}