You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you for today?

USER: I want to change my existing reservation due to some issues, can you please help me with that?

ASSISTANT: I am happy to help you in changing your reservation. Can you please provide your name to check the reservation status with your name in our booking list?

USER: Sure, I am Amy Hill.

ASSISTANT: Please wait for sometime to check our list.

USER: Ok.

ASSISTANT: I apologise to say this Amy Hill, there is no active reservation with your name in our booking list to change your reservation.

USER: Ok, not an issue. Thank you for your information.

ASSISTANT: You are welcome, thank you for choosing us. Hope you have a nice day ahead.