You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I help you?

USER: I need to change my reservation due to sudden guest visit to my house.

ASSISTANT: May I know your name to check the reservation?

USER: Sure, my name is Brandon King.

ASSISTANT: Ok, please wait a while I will check and revert to you.

USER: Sure.

ASSISTANT: Sorry, I found no reservation in your given name.

USER: Ok, no issue.

ASSISTANT: Thank you for reaching us regarding your existing reservation.

USER: Thanks for providing the information.