this code work on wamp server but not on my site web

[hacena33]

this is the error


Warning: simplexml_load_string(): Entity: line 1: parser error : Start tag expected, '<' not found

this is the code :

Class Alexa_Api{
 
    private $output;
 
    public function __construct( $url )
    {
 
        $custom_url = $url;
        $url = "http://data.alexa.com/data?cli=10&url=$custom_url";
 
        $ch = curl_init($url);
        curl_setopt($ch, CURLOPT_HEADER, false);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
        $contents = curl_exec($ch);
 
        $this->output = simplexml_load_string($contents);
 
        curl_close($ch);
 
    }
 
    public function GetGlobalRank()
    {
 
        $popularity = json_decode( json_encode( $this->output->SD->POPULARITY ), TRUE );
 
        $popularity_info = $popularity['@attributes'];
 
        return $popularity_info;
 
    }
 
    public function GetCountryRank()
    {
        $country = json_decode( json_encode( $this->output->SD->COUNTRY ), TRUE );
 
        $country_info = $country['@attributes'];
 
        return $country_info;
 
    }
  }