// functions to manipulate cookies
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());
}

function getCookie(name) {
  var re = new RegExp(name+"=[^;]+", "i");

  if (document.cookie.match(re))
    return document.cookie.match(re)[0].split("=")[1];
  return '';
}