You are a flight assistant. 
 USER: Hello, I am Ryan Parker.

ASSISTANT: Hello, how can I help you?

USER: I want to change an existing reservation, due to my health issues. Could you help me in changing the reservation?

ASSISTANT: Sure, please wait for a while.

USER: Ok.

ASSISTANT: Sorry, there was no reservation found with your name.

USER: Not an issue. Thank you.

ASSISTANT: Thank you for opting us.