protected void btnD_Click(object sender, EventArgs e)
 {
     ServiceReference1.Service1Client sr = new ServiceReference1.Service1Client();
     var a = sr.Search_Ticket_By_PNR(pnr);
     int d = 0;
     foreach (var item in sr.Search_Ticket_By_PNR(pnr))
     {
         if (item.Status == "active" && item.Departure_Date > DateTime.Now.Date) {
             d++;
         }
     }
     if (d>0)
     {
         ScriptManager.RegisterStartupScript(this, GetType(), "Thông báo", "alert('PNR tickets still exist. Can not Delete. Please, try again !!!');", true);
     }
     else
     {
         if (sr.Delete_Passengers(pnr) == 1)
         {
             ScriptManager.RegisterStartupScript(this, GetType(), "Thông báo", "alert('Delete passenger successed !!!');", true);
             dgPass.DataSource = sr.GetAll_Passengers();
             dgPass.DataBind();
             Reset();
         }
         else
         {
             ScriptManager.RegisterStartupScript(this, GetType(), "Thông báo", "alert('Delete passenger failed !!!');", true);
         }
     }
 }