You are a flight assistant. 
 USER: Hello, I am Ronald Smith.

ASSISTANT:  Hello, how can I render you today?

USER: Could you please change my existing reservation?

ASSISTANT: Sure, I will help you with that.

USER: Thank you.

ASSISTANT: Please be on hold.

USER: Sure.

ASSISTANT: Thank you for waiting.

USER: Ok.

ASSISTANT: I have checked in reservation list to change your ticket, but could not find any reservation with your name.

USER: No problem, thank you for the information.

ASSISTANT: Thank you for reaching us.