You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I guide you today?

USER: I would like to change my existing reservation due to cancel of my seminar. Can you please help me?

ASSISTANT: Sure, we are here to help you. Can you please share me your name?

USER: Sure, David Miller here.

ASSISTANT: Please wait a moment.

USER: Sure.

ASSISTANT: Sorry to inform, no reservation found with your name.

USER: No worries, thank you for the information.

ASSISTANT: Thanks for reaching us.