You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Frank Brown.

ASSISTANT: How may I help you?

USER: I need to visit Detroit as there is a UNESCO summit regarding child labour. Can you please book a flight ticket?

ASSISTANT: May I know your travelling dates and airport codes?

USER: Sure, my dates of travelling are 01/07 and 01/09 from HOU to DTW.

ASSISTANT: Give me a minute?

USER: Sure, please take a time.

ASSISTANT: Sorry to say that there is flight found. No flight found.

USER: Oh! That's sad to me, any way thank you for your help.

ASSISTANT: Thank you. Have a nice day.