You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you today?

USER: Can you help me to change the flight ticket which I had done a week ago on the name Gary Perez?

ASSISTANT: Sure, please wait for a moment.

USER: Ok, I will wait a moment.

ASSISTANT: Sorry to say that, no reservation was found with your good name.

USER: Ok, that is no a problem. Thank you for assisting me.

ASSISTANT: Thank you for reaching us.