You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I aid you?

USER: I am Kathleen Williams. Can you book a ticket for me from DCA to EWR?

ASSISTANT: May I know your trip dates?

USER: Sure, my preferable dates are 11/12 sand 11/14.

ASSISTANT: Sorry, no flights found.

USER: It's ok, thanks for your information.

ASSISTANT: Thank you for reaching us.