You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Anthony Mitchell.

ASSISTANT: How can I help you?

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

ASSISTANT: Please wait a moment.

USER: Sure.

ASSISTANT: Sorry, no reservation found by your name.

USER: Ok, no problem.

ASSISTANT: Thanks.

USER: Thanks for your informatin.