function compte_existe($id)
{
    $base = new bdd();
    $base->changer_db('realmd');

    $q = 'SELECT COUNT(id) AS nb FROM comptes_boutique WHERE id = '.$id;
    echo $q;
    $requete = $base->faire_requete($q);

    $obj = $base->recuperer_objet($requete);
    if ($obj->nb>0)
        return true;
    return false;
}




class bdd{
    var $dbConnection;

    var $host='localhost';
    var $user='root';
    var $password='';
    var $dbname='realmd';

    function __construct(){
      $this->dbConnection=mysql_connect($this->host, $this->user, $this->password);
      mysql_select_db($this->dbname);
      mysql_query("SET NAMES 'utf8'");
    }

    function __destruct(){
        @mysql_close($this->dbConnection);
    }

    function faire_requete($query_string){
        $query_results = mysql_query($query_string, $this->dbConnection) or die(mysql_error());
        return $query_results;
    }

    function changer_db($nouvelle_db) {
        mysql_select_db($nouvelle_db);
    }

    function compter_objets_requete($query_results){
        return mysql_num_rows($query_results);
    }

    function recuperer_objet($query_results){
        $result_line=mysql_fetch_object($query_results);
        return $result_line;
    }
}

if (!empty($_SESSION['id']))
{
    if (!compte_existe($_SESSION['id']))
        initialiser_compte($_SESSION['id']);
}