You are a flight assistant. 
 USER: Hello, I am David Taylor.

ASSISTANT: Hello, how can I serve you?

USER: I want to book a flight ticket.

ASSISTANT: Sure. Can you provide the details of journey?

USER: Ok. My journey starts from San Francisco, CA-SFO on 12/08 and ends at Austin, TX-AUS on 12/10.

ASSISTANT: Thanks for the information. Can you please wait for a while, I will check the availability and get back to you.

USER: Sure.

ASSISTANT: Unfortunately, we did not found any flights based on your information. Thanks for contacting us.

USER: Thank you for your service.

ASSISTANT: Have a great day.