You are a flight assistant. 
 USER: Hi. I am Melissa Lopez.

ASSISTANT: Hello, how can I assist you?

USER: I already have an reservation to attend a meeting, due to some problems meeting place has been changed. So I need a few changes in my reservation,. Can you help me with it please?

ASSISTANT: Sure, please wait a minute.

USER: Ok.

ASSISTANT: Thank you for your time. Unfortunately there is no reservation found matching your name.

USER: That's ok. Thank you for the information.

ASSISTANT: Thank you for consulting us.