<?php  include("includes/db_config.php"); 
if(isset($_POST["it_id"]))  
 {  $qty=$_POST["qty"];
      $query = "SELECT itd.* FROM ah_item_tracking_details itd WHERE itd.item_id = '".$_POST["it_id"]."'";  
      $result = mysqli_query($conn, $query);  
      $row = mysqli_fetch_array($result); 
      $stock= $row['opening_stock'];
      $mstock= $row['min_stock_quatity'];
      $quantity=$stock - $qty;
      $sql_prd ="UPDATE ah_item_tracking_details SET opening_stock='$quantity' WHERE item_id='".$_POST["it_id"]."'";
      $prd_res=mysqli_query($conn, $sql_prd) or die(mysqli_error());
      if($quantity == $mstock){
       $data="Your stock is ".$quantity." Please add more stock"; 
      }
      echo json_encode($data);  
    //  echo json_encode(array("dsamt"=>"$dsamt"));  
 }  
 ?>