Insert ข้อมูล ไม่ได้ ช่วยดู code ด้วยค่ะ INSERT INTO renew (id, startdate, enddate,) VALUES ('$id', '$startdate', '$enddate')

<?
$host="localhost";//�������
$user="root";//���ͼ����ҹ�ҹ������
$pass="";//���ʼ����ҹ�ҹ������
$db="4digits";//���Ͱҹ������

mysql_connect( $host,$user,$pass) or die ("�Դ��͡Ѻ�ҹ������ Mysql ����� ");
mysql_select_db($db) or die ("�������ö��Ҷ֧���ҧ��");
mysql_query("SET NAMES UTF8");
$sql =  "select * from renew" ;


$db_query=mysql_db_query($db,$sql);
$a=0;

while ( $result = mysql_fetch_array($db_query) )
{
$e=$result[enddate];
$s=$result[startdate];
$id = $result[id];
$ss = strtotime( $s );
$ee = strtotime( $e );
while (date('Y', $ss) < 2012 ) 
{
$startdate = mktime(0,0,0,date('m', $ss),date('d',$ss),date('y', $ss)+1);
$startdate = date( 'Y-m-d', $startdate );
$enddate = mktime(0,0,0,date('m', $ee),date('d',$ee),date('y', $ee)+1);
$enddate = date( 'Y-m-d', $enddate );
echo $id;
echo "/";
echo  $startdate;
echo  $enddate;
echo "<BR>";
$strSQL="INSERT INTO renew (id, startdate, enddate,) VALUES ('$id', '$startdate', '$enddate')";
echo $strSQL; 

$result=mysql_db_query($db,$strSQL);
$ss = strtotime( $startdate);
$ee = strtotime( $enddate);
$b++;
}
//$strSQL = "UPDATE renew SET renew.enddate = '$enddate' where id = $id " ;

$a++;
}
mysql_close() ;

?>