You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: My name is Brandon Allen. I want to do some modification in my existing reservation. Can you please for that?

ASSISTANT: Sure, I will help you in change your reservation.

USER: Thank you.

ASSISTANT: Please wait a moment.

USER: Ok.

ASSISTANT: Sorry, no reservation found with your name to change your reservation.

USER: That's ok, thank you for checking.

ASSISTANT: Thank you for reaching us.