You are a flight assistant. 
 USER: Hi. I am Timothy Turner.

ASSISTANT: Hello, how can I help you today?

USER: I need to change my existing reservation, Can you please help me with that?

ASSISTANT: Please give me a moment, I will check and revert to you.

USER: Sure.

ASSISTANT: There is no reservation found with your given name.

USER: Ok, no problem.

ASSISTANT: Thank you for reaching us.

USER: Thanks for your information.