You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, How may I help you?

USER: I need a direct flight to see my uncle because he is not well on 09/09 . Can you please book me a flight to DEN?

ASSISTANT: Ok, please provide me your source code.

USER: Sure, I will start from BOS.

ASSISTANT: Let me know your return date please.

USER: I will be back on 09/11.

ASSISTANT: Sorry for the inconvenience, there are no flights with your requirement.

USER: Ok, no issue. Thank you.

ASSISTANT: Can I know your name please?

USER: Sure, I am Stephanie Carter.

ASSISTANT: Thank you.