You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I am Joshua Hernandez. Can you please book a ticket from DCA to MSP?

ASSISTANT: Sure, please share your trip dates.

USER: My trip dates are on Feb 05 and Feb 07.

ASSISTANT: Do you have any other requirements?

USER: I need to depart at evening.

ASSISTANT: Sorry, we regret to inform you that there is no flight available as per your request.

USER: Ok, not a problem. Thank you.

ASSISTANT: My pleasure.