You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. Could you please tell me how may I assist you?

USER: My name is Matthew Scott.

ASSISTANT: Ok.

USER: I want to change my destination code in my recent reservation. So, can you please change my existing reservation?

ASSISTANT: Sorry to say, no reservation found on your details to change your reservation.

USER: Ok, no problem. Thank you for your support.

ASSISTANT: Thank you for contacting us.