You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you today?

USER: Due to an emergency work, I want to change my existing reservation.

ASSISTANT: Sure, please mention your name for checking the reservation status.

USER: My name is Dennis Thompson.

ASSISTANT: Please give me a moment.

USER: Sure.

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

USER: No problem, thank you.

ASSISTANT: Welcome, have a great day.