You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you at this moment?

USER: I am Katherine Martinez. Please book me a economy flight from DCA to MSP as my business meeting purpose.

ASSISTANT: Sure, I am happy to help you. Can you please tell me your planned travel dates?

USER: I have planned to travel on 01/17 and 01/19.

ASSISTANT: Ok, do you have any airlines preference?

USER: I am ok with any airline.

ASSISTANT: Sorry to inform you that, I haven't found any available flight in this route on the dates you have given.

USER: Ok, no problem. Thank you.

ASSISTANT: You are most welcome. Thank you for choosing us.