You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I aid you today?

USER: I want to change my reservation, can you help me with that?

ASSISTANT: Sure, I am here to help you out. Please provide me your name to check the reservation status.

USER: Please check the reservation under the name of Donald Clark.

ASSISTANT: Please allow me a moment.

USER: Sure.

ASSISTANT: Sorry Donald Clark, there is no active reservation on your name in our database.

USER: Ok, thank you.

ASSISTANT: Donald Clark, thank you for reaching us.