You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Charles Martinez.

ASSISTANT: How may I help you? Nice to meet you Charles.

USER: I want to book a ticket from IAD to JFK to attend workshop, can you help me in booking?

ASSISTANT: Sure, tell me your travel dates please?

USER: I am departing on Oct 07 and return on Oct 09.

ASSISTANT: Wait for a moment please.

USER: Sure, take your time.

ASSISTANT: Thanks for waiting. But I am sorry to say that there are no flights available.

USER: That's ok, thank you for your information.

ASSISTANT: Thank you.