You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I aid you today from my end?

USER: I would to like to alter my reservation, can you please help me with that?

ASSISTANT: Sure, I am here to help you out. Please provide me your name to check whether any active reservation is found on your name or not.

USER: Donald Hall here.

ASSISTANT: Please allow me a moment.

USER: Sure, take your time.

ASSISTANT: Ok, take your own time. Sorry, there is no reservation on your name in our database.

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

ASSISTANT: Thank you for reaching us.