You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you today?

USER: I would like to attend live music concert, can you please help me to reserve flight ticket from DCA to SFO?

ASSISTANT: Sure, we are here to help you. Kindly share your travel dates.

USER: Sure, my planned travelling dates are Jul, 19 and Jul, 21 respectively.

ASSISTANT: Do you have any connection limit?

USER: Flight has to be with single connection.

ASSISTANT: Is there any other specifications?

USER: Yes, I prefer to travel in business class.

ASSISTANT: May I know your name?

USER: Sure, my name is Nancy Turner here.

ASSISTANT: Ok, please wait a moment.

USER: Sure, I will wait.

ASSISTANT: Sorry to inform, no flights found with your requirement.

USER: Ok, not an issue. Thank you for your information.

ASSISTANT: Thanks for reaching us.