function setCookie(Name,Value,Duration){
  now = new Date();
  expiration = new Date(now.getTime()+Duration*86400000);
  document.cookie=Name+"="+Value+";expires="+expiration.toGMTString()+";";
}

setCookie("width",screen.width,1);
setCookie("height",screen.height,1);
setCookie("color",screen.colorDepth,1);