You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Ryan Wilson.

ASSISTANT: How may I help you today?

USER: I want to change my existing reservation due to bad weather condition, can you help me in changing reservation?

ASSISTANT: Sure, I am here to help you. Sorry, there is no reservation found on your name.

USER: Not am issue, thank you.

ASSISTANT: Thank you for reaching us.