You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I aid you?

USER: I would like to book a ticket from PHL to IAH, can you please help me out?

ASSISTANT: Sure, We are here to help you. Can I know your travelling dates?

USER: I am travelling on these dates Dec 18th and 20th.

ASSISTANT: Do you need any break?

USER: I need single connected flight.

ASSISTANT: May I know your name?

USER: Susan Evans here.

ASSISTANT: Is there any other specifications?

USER: I prefer return in the afternoon.

ASSISTANT:  We are unable to provide flight in between your journey routes due to some technical up-gradation at destination airport.

USER: Ok no problem, thank you for your services.

ASSISTANT: Thank you for reaching us.