You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I address you?

USER: I want to change my existing reservation. Can you please help me in that?

ASSISTANT: Sure, can you please mention your name?

USER: Kevin Evans here.

ASSISTANT: Ok, please wait.

USER: Sure.

ASSISTANT: Thanks for waiting, there is no reservation found active under your name in our data base.

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you for reaching us.