You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: I would like to change my flight reservation as my trip got postponed, can you please help me?

ASSISTANT: Sure, I am here to help you. May I know your name?

USER: My name is Karen Hall.

ASSISTANT: Thank you. Please be on hold for a while.

USER: Ok.

ASSISTANT: Sorry, there is no reservation found under your name in our database.

USER: Not an issue, thank you for the information.

ASSISTANT: You are most welcome.