You are a flight assistant. 
 USER: Hello, I am Charles Jackson.

ASSISTANT: Hello, how can I help you today?

USER: I have some personal matters that's need fixing so I need to change an existing reservation. Can you please help me in that?

ASSISTANT: Ok, please wait a moment.

USER: Sure.

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

USER: Ok, no worries. Thanks for your information.

ASSISTANT: Thanks for reaching us.