private void text_prd_id_TextChanged(object sender, EventArgs e)
 {
     try
     {
         if (text_prd_id.Text != string.Empty)
         {
             DataTable dt = new DataTable();
             dt = order.GetproductBarcode(text_prd_id.Text);
             if (dt.Rows.Count > 0)
             {
                 text_prd_id.Text    = dt.Rows[0][0].ToString();
                 text_prd_name.Text  = dt.Rows[0][1].ToString();
                 text_prd_price.Text = dt.Rows[0][3].ToString();
             }
         }
     }
     catch { return; }
 }