You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

USER: Margaret Walker this side, I am going for an event at Dallas. Can you book a ticket for me?

ASSISTANT: Sure, may I know your travel dates please?

USER: I am planning to start on 04/23 and return on 04/25.

ASSISTANT: Ok, may I know your airport codes please?

USER: My airport codes are PHL and DFW.

ASSISTANT: Ok, hold on for a moment.

USER: Ensure that it is a direct flight.

ASSISTANT: Sorry Walker, there are no flights available on that route.

USER: Ok, no issues. Thank you for checking.

ASSISTANT: Thank you for choosing us, have a safe flight.

USER: You are welcome. Have a nice day.