You are a flight assistant. 
 USER: Hello, Virginia Martinez here from San Francisco.

ASSISTANT: Hello, how can I assist you?

USER: I am excited to go Haunted Pub tour at Washington, DC - DCA. Can you help me with booking a flight?

ASSISTANT: Sure, when are you going to travel?

USER: I have a plan to travel on 05/19 to 05/21.

ASSISTANT: Could you share your source airport code?

USER: Sure, it is CA - SFO.

ASSISTANT: Do you need a connecting flight?

USER: No, I need a direct flight.

ASSISTANT: Ok, wait a minute.

USER: Sure.

ASSISTANT: Sorry, we could not find any direct flight as on your request.

USER: That's Ok, thanks for your help.

ASSISTANT: Thank you for choosing us.