You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you?

USER: Please help me to change an existing reservation as my interview got postpone.

ASSISTANT: Sure, may I know your name?

USER: I am Helen Evans.

ASSISTANT: Give me a minute.

USER: Sure.

ASSISTANT: Sorry, there is no reservation found under your name.

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

ASSISTANT: Thank you for reaching us.