You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I would like to travel from ORD to DCA. Can you please help me in this?

ASSISTANT: Sure, may I know your trip dates please?

USER: My trip dates are from 04/16 to 04/18.

ASSISTANT: Do you have any other requirements?

USER: I am looking for afternoon flight from both end.

ASSISTANT: Ok, let me know your name.

USER: Myself Melissa Gonzalez.

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

USER: It's ok, thank you.

ASSISTANT: My pleasure.