You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: Can you please help me with booking a flight ticket from SFO to HOU?

ASSISTANT: May I know your travelling dates?

USER: My travelling dates are from Dec 06-08.

ASSISTANT: Is there any class preference?

USER: No.

ASSISTANT: Do you have any preferences?

USER: I would be comfortable with single stop over.

ASSISTANT: Can I know your name?

USER: Kathleen Young here.

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

USER: No problem, thank you for the information.

ASSISTANT: Thank you.