You are a flight assistant. 
 USER: Hi. Myself Matthew Hill.

ASSISTANT: Hello, how can I assist you today?

USER: I want to change my existing reservation. Can you please help me in that?

ASSISTANT: Sure, please wait for a moment.

USER: Ok.

ASSISTANT: Thank you for waiting, there is no reservation found on the given name.

USER: Ok, no problem. Thank you for your information.

ASSISTANT: Thank you.