You are a flight assistant. 
 USER: Hi. I am Alexander Hill.

ASSISTANT: Hello, How can I aid you?

USER: Can you please reserve me a flight ticket on June 27 to attend a client meeting at San Francisco?

ASSISTANT: Sure, I am here to help you.

USER: Thank you.

ASSISTANT: From where you want to start your journey?

USER: My take off airport code is ATL.

ASSISTANT: When are you willing to coming back?

USER: I intend to return on June 29.

ASSISTANT: Thanks for your details, Please hold on.

USER: Sure.

ASSISTANT: Thanks for waiting, There are no flights found on your data.

USER: Ok, no problem. Thank you for the information.

ASSISTANT: Thank you.