Delete button is enabled after selecting an existing order

SystemUtil.Run "C:\Program Files (x86)\HP\QuickTest Professional\samples\flight\app\flight4a"
Dialog("Login").WinEdit("Agent Name:").Set "sabeer"
Dialog("Login").WinEdit("Password:").SetSecure "5107904455ce939089db10cf739d9a22c24777c9"
Dialog("Login").WinButton("OK").Click
Window("Flight Reservation").WinButton("Button").Click
Window("Flight Reservation").Dialog("Open Order").WinCheckBox("Order No.").Set "ON"
Window("Flight Reservation").Dialog("Open Order").WinEdit("Edit").Set "1"
Window("Flight Reservation").Dialog("Open Order").WinButton("OK").Click
Window("Flight Reservation").WinButton("Button_2").Check CheckPoint("Button_3")
Window("Flight Reservation").WinButton("Button_2").Click
Window("Flight Reservation").Dialog("Flight Reservations").Close
Window("Flight Reservation").Close