You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I help you?

USER: Will you please assist me in booking a flight ticket from SFO to HOU?

ASSISTANT: Could you let me know your travelling dates?

USER: My travelling dates are Dec 5th and Dec 7th.

ASSISTANT: Do you have any preference?

USER: I need a direct flight.

ASSISTANT: Can I know your name?

USER: Matthew Nelson.

ASSISTANT: Sorry, no flights found for your travelling dates.

USER: Ok, no problem.

ASSISTANT: Thank you.

USER: Thank you.