You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: My name is David Miller. I'm planning to visit Houston Zoo with my kids on 10/27.

ASSISTANT: Ok.

USER: Can you please book a ticket from SFO to IAH?

ASSISTANT: Sure. Can I know your journey dates?

USER: The dates are from 10/27 to 10/29.

ASSISTANT: Please wait for a moment.

USER: Ok.

ASSISTANT: Sorry David, there is no flight as per you details.

USER: That's ok.

ASSISTANT: Thank you for approaching us.

USER: Thank you.