var expDays = 1; // number of days the cookie should last
var page = "http://www.birdwatchersdigest.com/popup/choose_popup.php";
var windowprops = "width=300,height=350,location=no,toolbar=no,menubar=no,scrollbars=no,resizable=no,screenX=200,screenY=200,left=200,top=200";


function getCookieVal (offset) {
  var endstr = document.cookie.indexOf (";", offset);
  if (endstr == -1)
	endstr = document.cookie.length;
  return unescape(document.cookie.substring(offset, endstr));
}


function FixCookieDate (date) {
  var base = new Date(0);
  var skew = base.getTime(); // dawn of (Unix) time - should be 0
  if (skew > 0)  // Except on the Mac - ahead of its time
	date.setTime (date.getTime() - skew);
}


function GetCookie (name) {
  var arg = name + "=";
  var alen = arg.length;
  var clen = document.cookie.length;
  var i = 0;
  while (i < clen) {
	var j = i + alen;
	if (document.cookie.substring(i, j) == arg)
	  return getCookieVal (j);
	i = document.cookie.indexOf(" ", i) + 1;
	if (i == 0) break; 
  }
  return null;
}


function SetCookie (name,value,expires,path,domain,secure) {
  document.cookie = name + "=" + escape (value) +
	((expires) ? "; expires=" + expires.toGMTString() : "") +
	((path) ? "; path=" + path : "") +
	((domain) ? "; domain=" + domain : "") +
	((secure) ? "; secure" : "");
}


function DeleteCookie (name,path,domain) {
  if (GetCookie(name)) {
	document.cookie = name + "=" +
	  ((path) ? "; path=" + path : "") +
	  ((domain) ? "; domain=" + domain : "") +
	  "; expires=Thu, 01-Jan-70 00:00:01 GMT";
  }
}


function checkCount() {
	var count = GetCookie('count');
	var expdate = new Date ();
	FixCookieDate (expdate); // Correct for Mac date bug - call only once for given Date object!
	expdate.setTime (expdate.getTime() + (24 * 60 * 60 * 1000)); // 24 hrs from now 

	if (count == null) {
		count=1;
		SetCookie ("count", count, expdate, "/", "birdwatchersdigest.com", null);
		window.open(page, "", windowprops);

	} else {
		count++;
		SetCookie('count', count, expdate, "/", "birdwatchersdigest.com", null);
	}
}