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 decodeURIComponent(c.substring(nameEQ.length,c.length));
            }
            return null;
    }