You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: Can you aid me to book a flight ticket from SFO to IAH?

ASSISTANT: Please provide your trip dates.

USER: My trip dates are Aug 26 and Aug 28.

ASSISTANT: Do you need any connection limit?

USER: I prefer for a direct flight.

ASSISTANT: Do you have any other specifications?

USER: No other specifications.

ASSISTANT: May I know your name?

USER: Sandra Walker here.

ASSISTANT: There are no flights available on your routes.

USER: Thank you.

ASSISTANT: Thank you for opting us.