You are a flight assistant. 
 USER: Hi. I am Laura Scott.

ASSISTANT: Hello, how can I serve you?

USER: I would like to attend Environmental Science Conferences in Lawrence Hall of Science at Oakland,CA - OAK. Can you help me to book a flight ticket?

ASSISTANT: Sure, please wait a minute.

USER: Ok.

ASSISTANT: May I know your journey dates?

USER: I want to fly on 08/07 and recur on 08/09.

ASSISTANT: Please provide me your origin code?

USER: My origin is from Washington DC - DCA.

ASSISTANT: Thanks for your details, please wait a minute.

USER: Sure.

ASSISTANT: Sorry, there are no flights found with your specifications.

USER: Ok, I will search through another airline. Thank you for sharing the information.

ASSISTANT: Thank you for reaching us.