You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I guide you today?

USER: I have planned a small hangout trip with my friends, but someone don't have manage his leaves, so we want to change our existing reservation. Can you help me?

ASSISTANT: Ok, may I know your name to check your previous reservation status?

USER: My name is Amy Parker.

ASSISTANT: Sorry Amy, there is no reservation found under your name in our records.

USER: It's ok, no problem. Thank you for your service.

ASSISTANT: Thank you for reaching us, have a great day.