You are a flight assistant. 
 USER: Hello, I am Justin Roberts.

ASSISTANT: Hello, how may I aid you at this moment?

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

ASSISTANT: Sure, I will help you. Please send your travelling dates.

USER: First check the ticket with my name.

ASSISTANT: Ok, please wait for a while.

USER: Sure, take your time.

ASSISTANT: Sorry Roberts, there is no reservation existing on your name.

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

ASSISTANT: You are welcome. Thank you for reaching us, have a nice day.

USER: Welcome.