var cookie = "popup";
function toggle(div_id) {
	var el = document.getElementById(div_id);
	if ( el.style.display == 'none' ) {	el.style.display = 'block';}
	else {el.style.display = 'none';}
}
function blanket_size(popUpDivVar) {
	if (typeof window.innerWidth != 'undefined') {
		viewportheight = window.innerHeight;
	} else {
		viewportheight = document.documentElement.clientHeight;
	}
	if ((viewportheight > document.body.parentNode.scrollHeight) && (viewportheight > document.body.parentNode.clientHeight)) {
		blanket_height = viewportheight;
	} else {
		if (document.body.parentNode.clientHeight > document.body.parentNode.scrollHeight) {
			blanket_height = document.body.parentNode.clientHeight;
		} else {
			blanket_height = document.body.parentNode.scrollHeight;
		}
	}
	var blanket = document.getElementById('blanket');
	blanket.style.height = blanket_height + 'px';
	var popUpDiv = document.getElementById(popUpDivVar);
	popUpDiv_height=blanket_height/2-210; 
	//150 is half popup's height
	popUpDiv.style.top = popUpDiv_height + 'px';
}
function window_pos(popUpDivVar) {
	if (typeof window.innerWidth != 'undefined') {
		viewportwidth = window.innerHeight;
	} else {
		viewportwidth = document.documentElement.clientHeight;
	}
	if ((viewportwidth > document.body.parentNode.scrollWidth) && (viewportwidth > document.body.parentNode.clientWidth)) {
		window_width = viewportwidth;
	} else {
		if (document.body.parentNode.clientWidth > document.body.parentNode.scrollWidth) {
			window_width = document.body.parentNode.clientWidth;
		} else {
			window_width = document.body.parentNode.scrollWidth;
		}
	}
	var popUpDiv = document.getElementById(popUpDivVar);
	window_width=window_width/2-420;
	//150 is half popup's width
	popUpDiv.style.left = window_width + 'px';
}
function getcookie(cookieName) {
var id = cookieName + "=";
var cookievalue = "";

if (document.cookie.length > 0) {
offset = document.cookie.indexOf(id);
if (offset != -1) {
cookievalue = "x";
}
}
return cookievalue;
}

function setcookie () {

		var date = new Date();
		date.setTime(date.getTime()+(2*60*60*1000));
		var expires = "; expires="+date.toGMTString();

document.cookie = cookie + "=" + escape ("done")+expires+"; path=/";
}

function closepopup(windowname) { 
	blanket_size(windowname);
	window_pos(windowname);
	toggle('blanket');
	toggle(windowname);	
}
function popup(windowname) {
	if (getcookie(cookie)==""){
	blanket_size(windowname);
	window_pos(windowname);
	toggle('blanket');
	toggle(windowname);	
	setcookie();
	} else {  document.getElementById('blanket').style.display = 'none'; document.getElementById('windowname').style.display = 'none'; }
	
}