You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Kenneth Williams.

ASSISTANT: How may I aid you?

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

ASSISTANT: Sure, I am glad to help you with that.

USER: Thank you.

ASSISTANT: Please give me a moment to check your reservation status.

USER: Sure, take your time.

ASSISTANT: Sorry Williams, we couldn't find any reservation on your name in our records.

USER: Ok, not an issue. Thank you for your information.

ASSISTANT: Thank you for approaching us.