protected void Page_Load(object sender, EventArgs e)
 {
     if (!IsPostBack)
     {
         BindGridView();
         txtInvoiceNo.Focus();
         AppClass.CheckUserRightOnStockPage(this.Page);
         SetOnlyOneTab();
     }
     hdnPrintValue.Value = BAL.BALFactory.Instance.BAL_New_Bookings.FindDefaultPrinter(Globals.BranchID);
     hdnBranchId.Value   = Globals.BranchID;
     if (Request.Params["__EVENTTARGET"] as string == "drpStatus")
     {
         drpStatus_SelectedIndexChanged(null, EventArgs.Empty);
     }
 }