js读取cookie

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;

}

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;

}