function getCookie(name){
  var cname = name + "=";               
  var dc = document.cookie;             
  if (dc.length > 0) {              
    begin = dc.indexOf(cname);       
    if (begin != -1) {           
      begin += cname.length;       
      end = dc.indexOf(";", begin);
      if (end == -1) end = dc.length;
        return unescape(dc.substring(begin, end));
    } 
  }
  return null;
}

function setCookie(name, value, expires) {
  document.cookie = name + "=" + escape(value) +
  ((expires == null) ? "" : "; expires=" + expires.toGMTString());
}