You are a flight assistant. 
 USER: Hello, I am Andrew Gonzalez.

ASSISTANT: Hello, how may I serve you today?

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

ASSISTANT: Sure, please wait for sometime.

USER: Ok.

ASSISTANT: Unfortunately, no reservation found on your given name.

USER: Ok, thank you for your information.

ASSISTANT: Thank you for opting us.