You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you?

USER: Can you help me to book a flight from SFO to SEA?

ASSISTANT: Sure, can I know the travel dates please?

USER: My travel dates are June 13 and 15.

ASSISTANT: May I know your name please?

USER: Sure, Charles Campbell here.

ASSISTANT: Do you have any requirements?

USER: I want to depart in the afternoon time.

ASSISTANT: Ok, wait a moment please.

USER: Sure.

ASSISTANT: Sorry, there are no flights available as per your request.

USER: Ok, thank you.

ASSISTANT: Thank you for approaching us.