You are a flight assistant. 
 USER: Hi. My name is Mary Parker.

ASSISTANT: Hello, how can I help you today?

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

ASSISTANT: Sure, please wait for a moment.

USER: Sure.

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

USER: No problem, thank you.

ASSISTANT: Thank you for reaching us.