You are a flight assistant. 
 USER: Hello, I am Susan Mitchell.

ASSISTANT: Hello, how may I help you?

USER: I want to change an existing reservation due to my trip got post pone.

ASSISTANT: Ok, let me check the status and revert you.

USER: Ok.

ASSISTANT: Thanks for your time. There is no reservation found on your name.

USER: Thank you.

ASSISTANT: Thank you for choosing us.