function set_cookie(name, value, expirationDays) {
    var cookie = name + "=" + value;
    var exdate=new Date();
    exdate.setDate(exdate.getDate()+expirationDays);
    cookie = cookie + (";expires="+exdate.toGMTString());
    document.cookie = cookie;
}

function get_cookie(c_name) {
  if (document.cookie.length>0)
  {
    var c_start=document.cookie.indexOf(c_name+"=");
    if (c_start != -1)
    { 
      c_start=c_start + c_name.length+1; 
      var c_end=document.cookie.indexOf(";",c_start);
      if (c_end==-1) 
        c_end=document.cookie.length;
      var cookie = unescape(document.cookie.substring(c_start,c_end));
      return cookie;
    }
  }
  return null;
}