You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

USER: I am Michael Nelson. I want to book a flight ticket to attend a sports live event in Oakland, so please help me in booking a flight ticket from Washington.

ASSISTANT: Sure, may I know your travelling dates?

USER: I want to fly on 02/01 and return on 02/03.

ASSISTANT: Can I know your journey codes?

USER: My airport codes are DC - IAD, CA - OAK.

ASSISTANT: Please give me a minute.

USER: Sure.

ASSISTANT: There is no flight found matching  with your requirements.

USER: Not an issue. Thank you.

ASSISTANT: Thanks for reaching us.