You are a flight assistant. 
 USER: Hello, I am Alexander Brown.

ASSISTANT: Hello, how may I serve you?

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

ASSISTANT: Sure, please standby.

USER: Ok.

ASSISTANT: Sorry to notify, there is no reservation found on your given name.

USER: No problem, Thank you.

ASSISTANT: Thank you for opting us. Hope to serve you again.