You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you?

USER: Can you please help me to change my existing reservation, due to bad weather conditions?

ASSISTANT: Sure, may I know your name to check your reservation from our database?

USER: Sure, my name is Sharon Martin.

ASSISTANT: We regret to inform you that there is no active reservation found on your name to change.

USER: Ok, thank you.

ASSISTANT: Thank you for contacting us.