You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you?

USER: Please change my existing reservation owing to an emergency.

ASSISTANT: Ok, may I know your name?

USER: My name is Carol Lewis.

ASSISTANT: I have found your reservation, can you please tell me your new travelling airport codes?

USER: Airport codes are JFK and EWR.

ASSISTANT: May I know your new travelling dates?

USER: Departure is by 03/16 and 03/18 is return date.

ASSISTANT: Sorry, no flights found on your route.

USER: Thanks.

ASSISTANT: Most welcome.