You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I assist you today?

USER: I am Emily Carter. Can you help me in changing my existing reservation?

ASSISTANT: Ok, I will check for the flight ticket reservation availability in our records.

USER: Sure.

ASSISTANT: Ok, the reservation which you have asked is not found in our records of reservation.

USER: Ok, No issues. Thank you.

ASSISTANT: Thank you for choosing our agency, if you have any concern please check your mails.