You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you at this moment?

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

ASSISTANT: Sure, I am glad to help you out with that. Can you please share your name to check your previous reservation status?

USER: Thank you for the response, my name is Robert Williams.

ASSISTANT: Ok, please give me a moment.

USER: Ok, sure. I will wait for your response.

ASSISTANT: Sorry, there is no reservation found on your name in our records.

USER: Ok, not an issue. Anyways, thank you for the information.

ASSISTANT: Thank you for reaching us.