You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Gary Lopez.

ASSISTANT: In what way can I help you?

USER: I want to change my existing reservation due to bad weather condition, so please help me in change reservation.

ASSISTANT: Sure, please wait for a moment.

USER: Ok.

ASSISTANT: Thank you for waiting. There is no active reservation found on your name.

USER: No problem, thank you.

ASSISTANT: Thank you.