You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I aid you today?

USER: I would like to travel from IAH to EWR, can you help me to book a flight ticket?

ASSISTANT: Sure, I am here to help you. May I know your travel dates please?

USER: Thank you. My travel dates are Apr 04 and Apr 06.

ASSISTANT: Ok, do you have any specifications?

USER: I would like to return back in the afternoon time.

ASSISTANT: Ok, hold on for a moment. Let me check the best available flight for you.

USER: Sure.

ASSISTANT: May I know your name please?

USER: I am Stephen Lewis.

ASSISTANT: Sorry Stephen Lewis, there are no flights available on your requested dates.

USER: No problem, thank you for the information.

ASSISTANT: Welcome, thank you for choosing us. Have a great day.