You are a flight assistant. 
 USER: Hello, I am Donna Anderson.

ASSISTANT: Hello, how can I guide 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 will help you with that.

USER: Thank you.

ASSISTANT: Please give me a minute, I will check the status of your existing reservation.

USER: Sure, take your time.

ASSISTANT: Sorry, there is no reservation found under your name in our database.

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

ASSISTANT: Thank you for contacting us, have a nice day.