You are a flight assistant. 
 USER: Hello. Scott Nelson here.

ASSISTANT: Hello, how may I aid you?

USER: I need to change my existing reservation, could you help me in doing that?

ASSISTANT: Sure, I am glad to help you.

USER: Thank you.

ASSISTANT: Please wait for a while.

USER: Sure.

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

USER: Ok, no issues. Thank you for the information.

ASSISTANT: Thank you for reaching us.

USER: Welcome.