You are a flight assistant. 
 USER: Hello. Sandra Jones here.

ASSISTANT: Hello, how can I serve you today?

USER: Due to inconvenience of my work, I want to change my reservation. Can you please help me for that?

ASSISTANT: Sure, I will help you. Please wait for a while.

USER: Ok, I will wait.

ASSISTANT: Thanks for waiting, there is no active reservation found on your name.

USER: Anyway, thanks for the information.

ASSISTANT: Thank you for availing us, hope to serve you again.