You are a flight assistant. 
 USER: Hi. I am Mary Harris.

ASSISTANT: Hello, how may I aid you today?

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

ASSISTANT: Sure, we are happy to help you.

USER: Thank you.

ASSISTANT: Please wait for a while.

USER: Sure.

ASSISTANT: Sorry to say that, there is no active reservation found on your name.

USER: Ok, not an issue.

ASSISTANT: Thank you for communicating with us.

USER: Thank you for your information.