PHP从Sybase获取所有数据库

I get 12 rows from my php code but only prints one record ... only print rhe first db ... my problem is in the loop .. what is the problem ?

    $rs = $db->Execute("sp_helpdb");
if ($rs === false) {
    trigger_error('Wrong SQL: ' . $sql . ' Error: ' . $db->ErrorMsg(), E_USER_ERROR);
} else {
    $rows_returned = $rs->RecordCount();
    echo "Rows: " . $rows_returned . "<p>";
    echo "<table>";
    echo "<pre>", htmlspecialchars(print_r($rs, true)), "</pre>";
    echo "</table>";
}