You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I aid you?

USER: I want to book the flight ticket from IAD to EWR. Can you please help me?

ASSISTANT: Sure, can you share your trip dates?

USER: My travel dates are Oct 21 and Oct 23.

ASSISTANT: Do you have any preferences?

USER: I need a single connection flight.

ASSISTANT: May I know your name?

USER: Patricia Hall.

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

USER: Ok, thank you for the information.

ASSISTANT: Thank you for opting us.