You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you?

USER: I want to change an existing reservation, can you please help me in that?

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

USER: Thank you.

ASSISTANT: May I know your name please?

USER: My name is Ryan Perez.

ASSISTANT: Wait a moment please.

USER: Sure.

ASSISTANT: Ryan Perez, we haven't found found any reservation under your name in our database.

USER: Ok, that's not a problem. Thanks for your information.

ASSISTANT: Thank you for reaching us.