มีปัญหาเรื่อง query ข้อมูลใน php ออกมาจาก mysql ไม่ได้ ทั้งๆที่ query โดยตรงใน mysql ไม่มีปัญหา

<? 
include ('../dbopen.php');
echo 'test';
$sql = "SELECT S.CourseId, S.Section, S.TeacherId, S.TimeStart, S.TimeEnd, S.Type, P.pSessionDate, P.TimeIn, P.TimeOut\n"
        . "FROM ScheduledSession AS S, PresentingSession AS P\n"
        . "WHERE S.TeacherId = P.TeacherId AND S.TimeStart >= P.TimeIn AND S.TimeEnd <= P.TimeOut AND S.SessionDate = P.pSessionDate AND P.TeacherId = \'I999\' AND P.pSessionDate = \'2012/06/22\' LIMIT 0, 30 ";
$result = mysql_query($sql);
echo $result;

while ($rows = mysql_fetch_array($result)) {

    $CourseId = $rows['CourseId'];
    $Section = $rows['Section'];
    $TeacherId = $rows['TeacherId'];
    $TimeStart = $rows['TimeStart'];
    $TimeEnd = $rows['TimeEnd'];
    $Type = $rows['Type'];
    $pSessionDate = $rows['pSessionDate'];
    $TimeIn = $rows['TimeIn'];
    $TimeOut = $rows['TimeOut'];

    echo $TeacherId;
    echo '||';
    echo $CourseId;
    echo '||';
    echo $Section;
    echo '||';
    echo $TimeStart;
    echo '||';
    echo $TimeEnd;
    echo '||';
    echo $pSessionDate;
    echo '||';
    echo $TimeIn;
    echo '||';
    echo $TimeOut;
    echo '||';
    echo $Type;
    echo '<br/>';
}

include '../dbclose.php';
?>