You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Raymond Parker here.

ASSISTANT: How can I aid you?

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

ASSISTANT: Sure, please wait for a moment.

USER: Sure.

ASSISTANT: Sorry, Parker there is no reservation found on your name.

USER: Its ok, no problem.

ASSISTANT: Thank you for reaching us.

USER: Than you for your response.