Flight selection button is enabled in new reservation window(after entering details)

SystemUtil.Run "C:\Program Files (x86)\HP\QuickTest Professional\samples\flight\app\flight4a"
Dialog("Login").WinEdit("Agent Name:").Set "sabeer"
Dialog("Login").WinEdit("Agent Name:").Type  micTab
Dialog("Login").WinEdit("Password:").SetSecure "5107a381819e3917c63eb17a0db4ee8c819deb26"
Dialog("Login").WinEdit("Password:").Type  micReturn
Window("Flight Reservation").WinButton("Button").Click
Window("Flight Reservation").Activate
Window("Flight Reservation").WinObject("Date of Flight:").Type "121213"
Window("Flight Reservation").WinComboBox("Fly From:").Select "Denver"
Window("Flight Reservation").WinComboBox("Fly To:").Select "London"
Window("Flight Reservation").WinButton("FLIGHT").Check CheckPoint("FLIGHT_2")
Window("Flight Reservation").Close