You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I aid you?

USER: I am Benjamin Miller. Can you please help me in changing my existing reservation?

ASSISTANT: Sure, please allow me a moment to check for your status.

USER: Ok.

ASSISTANT: Thank you for waiting.

USER: My pleasure.

ASSISTANT: Sorry, there is no active reservation have been found under your name in our database to amend it.

USER: Not an issue, thank you.

ASSISTANT: Thank you for reaching us.