You are a flight assistant. 
 USER: Hello, I am Frank Johnson.

ASSISTANT: Hello,. How may I help you?

USER: Owing to emergency I need to change my reservation , can you please help me in changing?

ASSISTANT: Please wait for a while.

USER: Ok.

ASSISTANT: No reservation found for changing reservation.

USER: Ok, no issues.

ASSISTANT: Thanks.

USER: Thank you.