รบกวนช่วยดู code หน่อยค่ะ ว่าผิดตรงไหนเพราะไม่ทำการ insert และ update

for($i=3; $i<=16; $i++){
	 $select4=mysql_query("select*from crew_documents where cd_fk_cp_id = '".$crews."' and cd_fk_nd_id='".$i."'") or die (mysql_error());
	$num_rows4=mysql_num_rows($select4);
	if($num_rows4 == 0){
		
                if($_POST["cd_number_".$i]){
                    $strSQL3 = "INSERT INTO crew_documents VALUES( 
                        '".$_POST["cd_number_".$i]."',
                        '".$_POST["cd_date_issued_".$i]."',
                        '".$_POST["cd_date_expired_".$i]."',
                        '".$_POST["cd_country_".$i]."',
                        '".$_POST["cd_place_".$i]."',
                        '".$_POST["cd_authority_".$i]."',
                        '".$crews."', ".($i+1).", '1'
                    )";
                 $objQuery3 =   mysql_query($strSQL3);
				 echo ("<script>window.location='crew_profile_edit.php?id=".$crews."'</script>");		
                }
            }	
	
	else{

                if($_POST["cd_number_".$i]){
                    $strSQL4 = "update crew_documents set cd_number ='".$_POST['cd_number_'.$i]."',
                        cd_date_issued='".$_POST["cd_date_issued_".$i]."',
                        cd_date_expired='".$_POST["cd_date_expired_".$i]."',
                        cd_country='".$_POST["cd_country_".$i]."',
                        cd_place='".$_POST["cd_place_".$i]."',
                        cd_authority='".$_POST["cd_authority_".$i]."',
                        cd_fk_cp_id='".$crews."',cd_fk_nd_id= ".($i+1).",cd_status= '1'
						where cd_fk_cp_id='".$crews."' and cd_fk_nd_id=".($i+1)."
                    )";
                 $objQuery4 =   mysql_query($strSQL4);
				 echo ("<script>window.location='crew_profile_edit.php?id=".$crews."'</script>");		
                }
            }	
	}