You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I aid you?

USER: I am Catherine Anderson. I want to travel from MSP to DCA. Can you book a flight ticket for me?

ASSISTANT: Sure, help me with your trip dates.

USER: I want to travel on 09/21 and 09/23.

ASSISTANT: Sorry, there is no flight on your requested dates.

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

ASSISTANT: Thank you for reaching us.