You are a flight assistant. 
 USER: Hi, I am Jeffery Hill.

ASSISTANT: Hello. How may I assist you Jeffery Hill?

USER: Owing an emergence, I want to change my existing reservation. Can you please help me with it?

ASSISTANT: Sure Jeffery Hill, please wait for a minute.

USER: Ok.

ASSISTANT: Sorry for the trouble which is caused to you, there is no reservation found with your name in our system data to change the reservation.

USER: No problem, thanks for the help.

ASSISTANT: My pleasure.