You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Nancy Allen.

ASSISTANT:  How can I support you?

USER: I want to do some changes in existing reservation, due to sudden changes in climate my meeting has been postponed.

ASSISTANT: Ok, please wait I will revert you.

USER: Sure.

ASSISTANT: Sorry, no reservation was found on your requested dates.

USER: Ok, not an issue. Thank you for your response.

ASSISTANT:  Thank you for availing us.