You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you?

USER: I am planning to book a ticket from IAH to EWR. Can you please help me out?

ASSISTANT: Sure,  please provide your itinerary dates.

USER: I am planning to travel on Dec 15 and return back on Dec 17.

ASSISTANT: Do you prefer a direct or connecting flight?

USER: I am looking for a direct flight.

ASSISTANT: In which class do you prefer to travel?

USER: I am ok with any class.

ASSISTANT: Do you have any other specifications?

USER: No.

ASSISTANT: May I know your name?

USER: My name is Gregory Lee.

ASSISTANT: Sorry Gregory Lee, no direct flight is available on your route.

USER: That's fine, thank you for your service.

ASSISTANT: Thank you for reaching us.