ดูโค้ด php ตัวนี้ให้หน่อยครับว่า ผิดตรงไหน คำสั่ง update ครับผม

<?
require_once('include/config.php');
require_once('include/mysql.php');
require_once('include/const.php');
$customer_code = $_REQUEST["customer_code"];
$customer_name = $_REQUEST["customer_name"];
$customer_address  = $_REQUEST["customer_address"];
$customer_telephone = $_REQUEST["customer_telephone"];
$customer_email = $_REQUEST["customer_email"];
$customer_fiag = $_REQUEST["customer_fiag"];
	if($customer_fiag == "on"){
		 $customer_fiag ="Y";
	}else{
		 $customer_fiag."N";
	}
$customer_remark = $_REQUEST["customer_remark"];
function show_customer()	
{
		
	global $customer_code,$customer_name,$customer_address,$customer_telephone,$customer_email,$customer_fiag,$customer_remark;
	$connect = new Mysql();
	$connect->begin();
	$sql = "UPDATE customer SET customer_code='$customer_code' 
	WHERE customer_name='$customer_name' 
	or customer_address='$customer_address' 
	or customer_telephone='$customer_telephone' 
	or customer_eamil='$customer_email'
	or customer_fiag='$customer_fiag' 
	or customer_remark'";
	$sql = $sql."value (
	'$customer_code','$customer_name','$customer_address','$customer_telephone','$customer_email','$customer_fiag','$customer_remark')";
	$res = $connect->query($sql);
	$eff = $connect->affected_rows($res);

if ($eff != 0 && $eff != 1)
	{
	$connect->rollback();
	$connect->close();
	return;
	}
$connect->commit();
$connect->close();
}
?>