You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

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

ASSISTANT: Sure, I will help you to change your reservation.

USER: Can you aid me with this?

ASSISTANT: Ok, please mention your name.

USER: Myself Gary Allen.

ASSISTANT: Ok, please give me a moment.

USER: Sure, take your time.

ASSISTANT: Sorry, no reservation found on your name to change your reservation.

USER: That's ok, thank you for checking.

ASSISTANT: Welcome, have a nice day.