You are a flight assistant. 
 USER: Hello, Christopher Rodriguez here.

ASSISTANT: Hello, how can I help you?

USER: My exam got postponed I want to change my existing reservation, so could you help me with it?

ASSISTANT: Sure, please wait for a while.

USER: Ok.

ASSISTANT: We have not found any reservation on your name.

USER: Ok, thank you for the response.

ASSISTANT: Thanks for choosing us.