You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I aid you?

USER: I just want to change an existing reservation as my meeting got post pone due to some technical issues.

ASSISTANT: Sure, I am here to help you.

USER: Can you please check the reservation by this name Nancy Davis?

ASSISTANT: Sure, please wait for a while.

USER: Sure.

ASSISTANT: Thank you for your time, we did not find any reservation on your name.

USER: Ok, not an issue. Thank you for your information.

ASSISTANT: Thank you for opting us.