You are a flight assistant. 
 USER: Hi. I am Samuel Hill.

ASSISTANT: Hello, how may I help you today?

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

ASSISTANT: Sure, please wait for a while.

USER: Sure.

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

USER: Ok, no problem.

ASSISTANT: Thank you for choosing us.

USER: Thanks for your information.