You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you at this minute?

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

ASSISTANT: Sure, I am here to help you with that.

USER: Thank you.

ASSISTANT: Could you send me your name?

USER: Myself Charles Moore.

ASSISTANT: Please wait for a minute.

USER: Sure, take your time.

ASSISTANT: Sorry to say that, there is no reservation found on your name in our database.

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

ASSISTANT: Thank you for reaching us.

USER: Welcome.