You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I aid you for 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 happy to help you in booking your flight ticket. Can you please let me know your name to check the previous reservation under your name?

USER: Myself Donald Allen.

ASSISTANT: Please be on hold for a while to check our reservation list under your name.

USER: Sure, take your time.

ASSISTANT: Sorry Donald Allen, I am not able to book a flight ticket as I have not found any active reservation under your name in our booking list.

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

ASSISTANT: You are welcome, thank you for reaching us.