You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I help you today?

USER: Can you please help me in changing my existing reservation as my meeting got postponed?

ASSISTANT: Sure, we are here to help you.

USER: Thank you.

ASSISTANT: May I know your name to proceed further?

USER: I am Debra Thomas.

ASSISTANT: Ok, please wait for a while.

USER: Ok.

ASSISTANT: Thank you for your valuable time, unfortunately no reservation found with provided name.

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you for availing us.