You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I be your helping hand today?

USER: I am Dennis Campbell. I want to change my existing reservation due to heavy rainfall, can you please help me with that?

ASSISTANT: Sure, I will help you.

USER: Thank you.

ASSISTANT: Please hold on while I will check in the previous list and get back to you.

USER: Sure.

ASSISTANT: Thanks for your time, there is no active reservation found on your name to change.

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

ASSISTANT: Thank you for approaching us, hope to serve you again.