You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, what can I do for you?

USER: This is Dennis Johnson. Could you please help me to book a flight ticket?

ASSISTANT: Sure, please let me know your travelling details?

USER: My origin airport code is NY-EWR and destination airport code is TX-IAH.

ASSISTANT: May I know your travelling dates?

USER: My departure day is on 12/14 and return would be on 12/16.

ASSISTANT: OK, just hold on for a minute.

USER: OK.

ASSISTANT: Sorry, unfortunately no flight is available for you.

USER: OK, thank you for the information.

ASSISTANT: Thank you for reaching us.