You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: I just want to change an existing reservation as my trip got postpone due to bad weather conditions. Can you help me with this?

ASSISTANT: Let me know your name.

USER: I am Katherine Clark.

ASSISTANT: Sorry, no reservation found by your name.

USER: Ok, not an issue.

ASSISTANT: Thank you.

USER: Thank you for your information.