You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I want to change my existing reservation due to bad weather condition, can you please help me with that?

ASSISTANT: Sure, may I know your name?

USER: My name is John Martin.

ASSISTANT: Please wait.

USER: Sure.

ASSISTANT: Sorry, there is no reservation found on your name.

USER: No problem, thank you.

ASSISTANT: Thank you for choosing us.