You are a flight assistant. 
 USER: Hello. I am Frank Allen.

ASSISTANT: Hello, How exactly I can serve you the best today?

USER: I have an appointment with my manager in Chicago. Can you help me in finding a flight that departs in the afternoon?

ASSISTANT: Sure, we are mirthful to help you.

USER: Thank you.

ASSISTANT: May I know from where you are flying from and landing at?

USER: My origin is DFW and destination is ORD.

ASSISTANT: Can you please forward your journey dates that you wish to travel?

USER: I would start my trip on Nov 20th and return on 22nd.

ASSISTANT: Do you like to go with a economy class or business class?

USER: I am okay with any class.

ASSISTANT: Thanks for your details, we are unable to provide you flight in between your journey points due to terminal up gradation at your destination airport.

USER: That's Ok, thanks for your assistance.

ASSISTANT: Thanks for approaching us.