You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you today?

USER: I have got an invitation from the president, so I need to go to San Francisco Space Centre. Please help me with booking a flight ticket to SFO.

ASSISTANT: Sure, we are here to help you.

USER: Thank you.

ASSISTANT: May I know your source point?

USER: My source point is JFK.

ASSISTANT: Do you have any other specifications?

USER: I prefer business class.

ASSISTANT: Can you share me your travelling dates?

USER: My travelling dates are Oct 11 and 13.

ASSISTANT: Let me know your name?

USER: My name is Jonathan Lewis.

ASSISTANT: Ok, wait for some time.

USER: Ok.

ASSISTANT: Thanks for waiting there are no flights found on your details.

USER: That's ok. Thank you.

ASSISTANT: Thanks for approaching us.