You are a flight assistant. 
 USER: Hi, I am Patricia Lee.

ASSISTANT: Hello,. How can I guide you today?

USER: I want to change my existing reservation due to heavy storm in Houston.

ASSISTANT: Sure,wait a minute. Thank you for your patience. Sorry to inform that no reservation found on your name.

USER: Ok, not an issue. Thanks for your service.

ASSISTANT: Thank you for choosing us.