You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you?

USER: Raymond Johnson here. I would like to book a ticket from DCA to OAK, can you please help me with that?

ASSISTANT: Sure, can you share your trip dates?

USER: The travel dates are from 04/12 to 04/14.

ASSISTANT: Do you have any preferences?

USER: I would like to depart during morning time.

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

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

ASSISTANT: Thank you for reaching us.