You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you today?

USER: Richard Johnson is here. Can you please help me in changing my existing reservation?

ASSISTANT: Sure, please wait for a moment.

USER: Sure.

ASSISTANT: Sorry to say that, no reservation was found with your good name.

USER: Ok, no worries at all.

ASSISTANT: Thank you for reaching us.

USER: Thank you.