You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I support you?

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

ASSISTANT: Sure, we are here to help you.

USER: Thank you.

ASSISTANT: On whose name, the reservation has been made earlier?

USER: Sure, Donald Thomas here.

ASSISTANT: Please wait for a while.

USER: Sure.

ASSISTANT: Thanks for your time, there is no active reservation found in your name to change.

USER: No problem, thank you for the information.

ASSISTANT: Thank you for availing us.