You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you today?

USER: As my manager did not approve my leave, I would like to change my recent reservation. Can you aid me with this?

ASSISTANT: I am sorry to know that . I will help you.

USER: Thank you.

ASSISTANT: Please let me know with your name.

USER: Myself Jack Miller.

ASSISTANT: Please allow me a minute.

USER: Sure, take your time.

ASSISTANT: Jack Miller, I am really sorry to inform you that there is no booking done on your name.

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

ASSISTANT: Thank you for reaching us. Have a great time!.