You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I assist you today?

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

ASSISTANT: Sure, will you mention your name for checking the reservation?

USER: Myself Frank Perez.

ASSISTANT: Please wait a moment.

USER: Ok.

ASSISTANT: Thanks for waiting, there is no reservation found under your name.

USER: No problem, thanks for checking.

ASSISTANT: Welcome, have a great day.