function readCookie(name)
{
  var cookieValue = "";
  var search = name + "=";
  if(document.cookie.length > 0)
  {
    offset = document.cookie.indexOf(search);
    if (offset != -1)
    {
      offset += search.length;
      end = document.cookie.indexOf(";", offset);
      if (end == -1) end = document.cookie.length;
      cookieValue = unescape(document.cookie.substring(offset, end))
    }
  }
  return cookieValue;
}
function writeCookie(name, value, hours)
{
  var expire = "";
  if(hours != null)
  {
    expire = new Date((new Date()).getTime() + hours * 3600000);
    expire = "; expires=" + expire.toGMTString();
  }
  document.cookie = name + "=" + escape(value) + expire + '; path=/ ; domain=.youban.com';
}