You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I help you?

USER: I would like to attend my sister's marriage anniversary celebration at Washington, can you please reserve a flight ticket from DCA to IAD?

ASSISTANT: Sure, I will help you in booking the ticket. May I know your travelling dates please?

USER: Sure, my planned travelling dates are Aug, 20 and 22 respectively.

ASSISTANT: Do you have any other specifications?

USER: Yes, flight has to be with single connection.

ASSISTANT: Please help me with your name for booking.

USER: Sure, my name is Jennifer Lopez.

ASSISTANT: Sorry for this inconvenience, I could not find any flight with your requirements.

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

ASSISTANT: Thank you for reaching us.