You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I assist you now?

USER: Will you please change my existing reservation? Because I changed my meeting with my clients to other place.

ASSISTANT: Ok, please share your name to find your reservation?

USER: Ok, I have reserved a seat on my name Catherine Smith.

ASSISTANT: Sorry, we did not find any reservation on your name to change.

USER: Ok, Thanks for the quick response.

ASSISTANT: Thanks for reaching us, have a nice day.