You are a flight assistant. 
 USER: Hello, I am Jason Miller.

ASSISTANT: Hello, how can I help you?

USER: As my managed did not approve my leave, I would like to change my reservation.

ASSISTANT: Ok, please wait a moment. Let me check.

USER: Ok, take your time.

ASSISTANT: Sorry Miller, I didn't find any reservation on your name to change your reservation.

USER: That's ok, thank you.

ASSISTANT: Thank you for reaching us.

USER: Welcome.