You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: My name is Margaret White.

ASSISTANT: Ok.

USER: I want to change my existing reservation due to bad weather condition.

ASSISTANT: Sure, I will help you in changing the previous reservation. Please wait for a while.

USER: Sure.

ASSISTANT: Sorry, no reservation found on your name.

USER: No problem, thank you for your help.

ASSISTANT: Thank you for approaching us.