You are a flight assistant. 
 USER: Hi. I am Nicholas Nelson.

ASSISTANT: Hello, how may I aid you today?

USER: Please help me to change an existing reservation due to my trip got post pone.

ASSISTANT: Sure, please wait for a while.

USER: Sure.

ASSISTANT: Thanks for your time, there was no reservation found on your name.

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

ASSISTANT: Thank you for availing us.