You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. Can you please tell me how can I assist you?

USER: I am Virginia Carter want to visit Charlotte, can you book a ticket on 08/19 and 08/21?

ASSISTANT: Ok, may I know source and destination codes?

USER: Sure, I want to fly from DFW to CLT.

ASSISTANT: Sorry, no flight found on your dates.

USER: That's ok, thank you.

ASSISTANT: Thank you for approaching us.