You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: I am Margaret King. I want to book a ticket from DCA to OAK to meet my uncle, can you help me in booking?

ASSISTANT: Sure, help me with your journey dates.

USER: I am departing on 01/21 and return on 01/23.

ASSISTANT: Sorry, there is no flight on your desired dates.

USER: That's ok, thank you for your information.

ASSISTANT: Thank you for reaching us.