You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I aid you?

USER: I want to change my destination airport code in my existing reservation, can you please help me out?

ASSISTANT: Sure, may I know your name?

USER: Sure, my name is Eric Young.

ASSISTANT: We found your reservation,  can you share your journey dates?

USER: Sure, my trip dates are Apr 17 and Apr 19.

ASSISTANT: May I know your airport codes?

USER: Sure, my location airport codes are EWR and BOS.

ASSISTANT: Do you have any preferences?

USER: Yes, I am looking for a direct flight.

ASSISTANT: There is  a connecting flight with number 1019 in airline Frontier, the fare is 100 in economy class. Can I book it?

USER: My depart time must be afternoon.

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

USER: It's ok, thank you for the information.

ASSISTANT: Thank you for opting us.