You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you?

USER: Will you please assist me to change my existing reservation as my plan to meet my friend got postponed?

ASSISTANT: Sure, I am here to help you. May I know your name?

USER: I am William Walker.

ASSISTANT: Ok, please wait for a moment.

USER: Sure.

ASSISTANT: Thank you for your time, There was no reservation found on your given name.

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

ASSISTANT: Thank you for choosing us.