function createCookie(name,value,days) {
	if (days) {
		var date = new Date();
		date.setTime(date.getTime()+(days*24*60*60*1000));
		var expires = "; expires="+date.toGMTString();
	}
	else var expires = "";
	document.cookie = name+"="+value+expires+"; path=/";
}

function readCookie(name) {
	var nameEQ = name + "=";
	var ca = document.cookie.split(';');
	for(var i=0;i < ca.length;i++) {
		var c = ca[i];
		while (c.charAt(0)==' ') c = c.substring(1,c.length);
		if (c.indexOf(nameEQ) == 0) return c.substring(nameEQ.length,c.length);
	}
	return null;
}

function eraseCookie(name) {
	createCookie(name,"",-1);
}


var search = window.location.search.substring(1).split('&');
for ( var i=0; i<search.length; i++ ){
	var parts = search[i].split('=');
	parts[0] = decodeURIComponent(parts[0]);
	parts[1] = decodeURIComponent(parts[1]);
	if ( parts[0] == 'promo' ){
		createCookie('promo_code', parts[1], 365);
		break;
	}
}

var promo_code = readCookie('promo_code');