You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

USER: I would like to change my reservation because of sudden accident of my aunt, can you help me?

ASSISTANT: Sure, may I know your name please?

USER: My name is Anna Lewis.

ASSISTANT: Ok Anna, please wait for a moment.

USER: Ok.

ASSISTANT: Sorry Anna Lewis, there is no reservation found as per your name to change any reservation.

USER: No problem, sorry for troubling you.

ASSISTANT: Thank you, for contacting us.

USER: Thanks for your humble service.