You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I be there for you?

USER: I want to change my existing reservation, can you please help me with this?

ASSISTANT: Sure, will you please let me know on what name the reservation was done formerly?

USER: I am Gregory Lewis.

ASSISTANT: Ok, please wait.

USER: Sure.

ASSISTANT: Thanks for waiting Gregory Lewis, we could not find any reservation active by your name.

USER: Ok, no problem. Thank you for your information.

ASSISTANT: Thank you for approaching us.