<?php
require_once'class.crud.php';

$id = $_GET['id'];
 if(isset($_GET['id'])){
   $kode = $_GET['id'];
   $sql = mysql_query("SELECT * FROM barang WHERE kd_barang='$kode'");
   $kueri = mysql_query($sql);
}
   while ($data= mysql_fetch_assoc($kueri)) {
    # code...

   $namabrg = $data['nama_barang'];
   $harga_beli = $data['harga_satuan'];
   $harga_jual = $data['harga_jual'];
   $stok = $data['stok'];

};