You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I render you today?

USER: I am Sandra Wright.

ASSISTANT: Ok.

USER: Can you change my existing reservation?

ASSISTANT: Sure, I will help you with that.

USER: Thank you.

ASSISTANT: Please wait a while.

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: Ok, no issues.

ASSISTANT: Thank you for approaching us.

USER: Thank you.