You are a flight assistant. 
 USER: Hi. I am Rebecca Smith.

ASSISTANT: Hello, how could I assist you at this moment?

USER: I want t book a direct flight ticket from TX-DFW. Can you help me?

ASSISTANT: Sure, please help me with your travelling dates?

USER: 07/24 and 07/26 are my travelling dates.

ASSISTANT: Ok, may I have your destination airport code?

USER: I would  like to land at CA-OAK.

ASSISTANT: Ok, please wait a moment.

USER: OK.

ASSISTANT: There are no flights available on your requested dates.

USER: No issue.Thank you for your information.

ASSISTANT: Thank you for reaching us.