Insert ข้อมูลไม่ลงฐานข้อมูล ไม่ขึ้น ฟ้องอะไรเลย แต่ข้อมูลไม่ลง

<?php
include_once 'verify.php';
include_once '../config/config.php';

require_once '../class/dbconnect.php';
require_once '../class/main.php';

$db = new dbconnect();
$main = new main();
$filter=$_GET['filter'];
$pid=$_GET['pid'];
$action=$_GET['action'];
$refpage=$_SERVER['HTTP_REFERER'];
 if($action=='del'&&$pid!=''){
    $main->confirm('Are you sure you want to delete.', $refpage);
    $sqlstr="DELETE FROM product WHERE product_id='$pid'";
    $db->query($sqlstr,'1');
    unlink("../file/product/$pid.jpg");
    unlink("../file/product/$pid_s.jpg");
    $main->redirect($refpage);
    exit;
}
elseif($action=='edit'&&$pid!=''){
    $sqlstr="SELECT * FROM product WHERE product_id='$pid'";
    $result=$db->query($sqlstr);
}
elseif($action!='add'){
    $main->alert('Wrong format url.');
    $main->redirect($refpage);
    exit;
}
if($_POST){
    $name_th=$_POST['name_th'];
    $name_en=$_POST['name_en'];
    $detail_th = $_POST['detail_th'];
    $detail_en = $_POST['detail_en'];
    $product_num = $_POST['pnum'];
    $status=$_POST['status'];
    if(!$name_th&&!$name_en){
        $main->alert('Plase input both names.');
        $main->redirect($refpage);
        exit;
    }
    if($action=='add'){
        if(!$_FILES["product_image"]["name"]){
            $main->alert('Plase upload file.');
            $main->redirect($refpage);
            exit;
        }
        else{
            $sqlstr="INSERT INTO product (name_th,name_en,detail_th,detail_en,product_num,status,cat_id) VALUES ('$name_th','$name_en','$detail_th','$detail_en','$product_num','$status','$filter')";
            $db->query($sqlstr,'1');
            $lq=mysql_insert_id();
            $allowedExtensions = array("jpg","jpeg","gif","png");
            $ext=end(explode(".",strtolower($_FILES["product_image"]["name"])));
            if(!in_array($ext,$allowedExtensions)) {
                $main->alert($_FILES["product_image"]["name"].' is invalid file type');
                $main->redirect('product_form.php');
                exit;
            }
            else{
                move_uploaded_file($_FILES["product_image"]["tmp_name"],"../images_product/$lq.jpg");
            }
            $main->redirect("product_list.php?filter=$filter");
        }
    }
    if($action=='edit'){
        if($_FILES["product_image"]["name"]){
            $allowedExtensions = array("jpg","jpeg","gif","png");
            $ext=end(explode(".",strtolower($_FILES["product_image"]["name"])));
            if(!in_array($ext,$allowedExtensions)) {
                $main->alert($_FILES["product_image"]["name"].' is invalid file type');
                $main->redirect('product_form.php');
                exit;
            }
            else{
                move_uploaded_file($_FILES["product_image"]["tmp_name"],"../images_product/$pid.jpg");
            }
        }
        $sqlstr="UPDATE product SET name_th='$name_th',name_en='$name_en',detail_th='$detail_th',detail_en='$detail_en',product_num='$product_num',status='$status' WHERE product_id='$pid'";
        $db->query($sqlstr,'1');
        $main->redirect("product_list.php?filter=$filter");
    }
    
}
include_once 'header.php';
?>
<table class="body" width="100%" align="top" border="0" cellspacing="10">
    <tr>
        <td width="200" valign="top">
            <?php
                include_once 'menu.php';
            ?>
        </td>
        <td valign="top">
			<p class="text-title" style="margin-top: 0px; margin-bottom: 0px;"><? if($action=='add') echo 'Add'; elseif($action=='edit') echo 'Edit';?> Product page.</p>
            <form enctype="multipart/form-data" name="form_newsevent_form" id="form_newsevent_form" method="post" action="">
                <table class="content" width="100%" align="top" border="0">
                    <tr>
                        <td>
                            Upload picture. SIZE:200x280 or 280x200<?if($action=='edit') echo'<a class ="colorbox" href="../images_product/'.$pid.'.jpg"><img alt="preview" src="../images/preview.png"/></a>'?>
                        </td>
                    </tr>
                    <tr>
                        <td>
                            <input type="file" name="product_image" id="product_image" size="20"/>
                        </td>
                    </tr>
                    <tr>
                        <td>
                            Name <img alt="thai" src="../images/th.png">
                        </td>
                    </tr>
                    <tr>
                        <td>
                            <input type="text" name="name_th" id="name_th" size="100" value="<?echo $result[0]['name_th'];?>"/><font color="red">*</font>
                        </td>
                    </tr>
                    <tr>
                        <td>
                            Name <img alt="english" src="../images/us.png">
                        </td>
                    </tr>
                    <tr>
                        <td>
                            <input type="text" name="name_en" id="name_en" size="100" value="<?echo $result[0]['name_en'];?>"/><font color="red">*</font>
                        </td>
                    </tr>
                    <tr>
                        <td>
                            Detail <img alt="thai" src="../images/th.png">
                        </td>
                    </tr>
                    <tr>
                        <td>
                            <textarea name="detail_th" id="detail_th" cols="100" rows="7"><?echo $result[0]['detail_th'];?></textarea>
                        </td>
                    </tr>
                    <tr>
                        <td>
                            Detail <img alt="english" src="../images/us.png">
                        </td>
                    </tr>
                    <tr>
                        <td>
                            <textarea name="detail_en" id="detail_en" cols="100" rows="7"><?echo $result[0]['detail_en'];?></textarea>
                        </td>
                    </tr>
                    <tr>
                        <td>
                            Product numbers.
                        </td>
                    </tr>
                    <tr>
                        <td>
                            <textarea name="pnum" id="pnum" cols="100" rows="7"><?echo $result[0]['product_num'];?></textarea>
                        </td>
                    </tr>
                    <tr>
                        <td>
                            <input type="checkbox" name="status" value="1" <? if($result[0]['status']) echo "checked";?>>Publish
                        </td>
                    </tr>
                    <tr>
                        <td>
                            <input type="submit" value="Submit"/>
                        </td>
                    </tr>
                </table>
            </form>
        </td>
    </tr>
</table>
<?php
include_once 'footer.php';
?>