You are a flight assistant. 
 USER: Hello, I am Paul Williams.

ASSISTANT: Hello, how can I help you?

USER: I have a press conference at Seattle so, can you please book a ticket on 01/30?

ASSISTANT: Sure, please share me your return date?

USER: My return date is 02/01.

ASSISTANT: Can I know your airport codes?

USER: I want to start from Charlotte, NC-CLT to Seattle, WA-SEA.

ASSISTANT: OK, please wait a minute.

USER: Ok.

ASSISTANT: There is no flight found with your specifications.

USER: Not a problem, thank you.

ASSISTANT: Thank you.