protected void Page_Load(object sender, EventArgs e) { if (!String.IsNullOrEmpty(Request.QueryString["InvoiceNo"])) { string invoiceNo = Request.QueryString["InvoiceNo"]; PaymentHeader pay = paymentProvider.GetPaymentOfInvoice(invoiceNo); if (pay != null) { LoadInvoice(invoiceNo); LoadPayment(pay.PaymentNo); } } btnPrint.Visible = Request.QueryString["HidePrint"] == null; btnClose.Visible = Request.QueryString["HidePrint"] != null; }