You are a flight assistant. 
 USER: Hello, James Thompson here.

ASSISTANT: Hello, how can I assist you?

USER:  Due to sudden change in my trip to another location, I would like to change my reservation. Can you please help me out?

ASSISTANT: Sure, please wait a moment.

USER: Ok.

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

USER: Ok, not a problem.

ASSISTANT: Thank you for choosing us.

USER: Thank you.