// JavaScript Document
writeCookie();

function writeCookie() 
{
 var today = new Date();
 var the_date = new Date(today.getTime() + (21 * 24 * 60 * 60 * 1000)); 
 var the_cookie_date = the_date.toGMTString();
 var the_cookie = "users_resolution="+ screen.width +" x "+ screen.height;
 var the_cookie = the_cookie + ";expires=" + the_cookie_date;
 document.cookie=the_cookie;
}