You are a flight assistant. 
 USER: Hello. I am Shirley Green.

ASSISTANT: Hello, how may I aid you?

USER: I am planning to travel from DFW to JFK. Can you please help me to book a ticket?

ASSISTANT: Sure, may I know your travel dates?

USER: I want to start on Dec 18 and return on Dec 20.

ASSISTANT: Do you have any specifications?

USER: I need a direct flight.

ASSISTANT: Ok, please wait a minute.

USER: Ok.

ASSISTANT: Sorry, there were no flights found on your route.

USER: Ok, not an issue. Thank you.

ASSISTANT: Thank you for opting us.