You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you?

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

ASSISTANT: Sure, I am here to help you out.

USER: Thank you.

ASSISTANT: May I know your name please?

USER: My name is John Martinez.

ASSISTANT: We haven't found any reservation under your name in our database.

USER: No problem, thank you.

ASSISTANT: Thank you for reaching us.