You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: Can you please help me in booking my flight ticket from HOU to BOS?

ASSISTANT: May I know your travelling dates?

USER: Sure, my travelling dates are from 07/14 to 07/16.

ASSISTANT: Do you have any preferences?

USER: Yes, I need a direct flight.

ASSISTANT: Please let me know your name?

USER: Myself Charles Robinson.

ASSISTANT: Sorry, there is no flight for your travelling dates.

USER: It's ok, thank you for your help.

ASSISTANT: Thank you.