You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. What can I do for you today?

USER: I would like to meet my school friend on his birthday, can you please help me to book the flight ticket from OAK to DCA?

ASSISTANT: Ok, may I know your name please?

USER: My name is David Lewis.

ASSISTANT: Can you mention your planned dates for the following journey? So, I can check with the availability for you.

USER: I want to depart on 05/10 and return on 05/12.

ASSISTANT: Ok, please give me a minute to check for the availability for you.

USER: Sure.

ASSISTANT: Thank you for waiting David Lewis. There is no flight found on your requested route.

USER: Sad to hear that, anyway thank you for checking.

ASSISTANT: Sorry for the inconvenience, thank you for reaching our agency.