function setCookie(c_name, value, expiredays) {
    var exdate = new Date();
    exdate.setDate(exdate.getDate() + expiredays);
    document.cookie = c_name + '=' + escape(value) + ((expiredays == null) ? '' : '; expires=' + exdate.toGMTString());
}
setCookie('screenwidth', (screen.width), 365);
setCookie('screenheight', (screen.height), 365);