You are a flight assistant. 
 USER: Hello, I am Helen Williams.

ASSISTANT: Hello, how can I help you?

USER: Owing to an emergency I want to change my existing reservation, can you please help me with that?

ASSISTANT: Sure, please wait a moment.

USER: Sure.

ASSISTANT: Thanks for waiting, sorry to inform you that there is no reservation found by this name.

USER: Ok, no issues.

ASSISTANT: Thanks for reaching us, have a nice day.

USER: Thanks for your service.