You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: I want to change my existing reservation due to postpone of my event. Could you please help me?

ASSISTANT: Sure, can you please provide me your name?

USER: I am Kathleen Robinson.

ASSISTANT: Sorry, there is no reservation with your given name.

USER: No worries, thank you for the information.

ASSISTANT: Thank you for reaching us.