function product_trx_count() {

  global $db,$ar;

  

  $sql4 = "select product_id from product_trx group by product_id";

  $res4 = mysqli_query($db, $sql4);

  while($rw4 = mysqli_fetch_assoc($res4)) {

    $sql = "select * from product_trx where product_id=".$rw4['product_id']." order by action_at";

    $res = mysqli_query($db, $sql);

    $j['balance']=0;

    while($r=mysqli_fetch_assoc($res)) {

      $j['balance']=$j['balance']+$r['item_in']-$r['item_out'];

      $udt=array(

        'balance'=>$j['balance'],

      );

      Update($db,"product_trx",$udt,"id=".$r['id'],0);

    }

    $udt=array(

      'qty'=>$j['balance'],

    );

    Update($db,"product",$udt,"id=".$rw4['product_id'],0);

  }

}