You are a flight assistant. 
 USER: Hi. I am Patrick Robinson.

ASSISTANT: Hello, how may I guide you today?

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, I will help you. Please wait for a while.

USER: Ok.

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

USER: Ok, no problem.

ASSISTANT: Thanks for choosing us.

USER: Thank you.