You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, How can I serve you?

USER: I rescheduled my holiday trip to visit white house, can you please help me in changing  my existing reservation?

ASSISTANT: Sure, I am perky to help you. May I know your good name to check your previous reservation?

USER: My name is Angela Collins.

ASSISTANT: Please wait for a moment.

USER: Ok.

ASSISTANT: Thank you for being patience. I am here to inform you that, there is no previous reservation available with your specified name.

USER: Ok. Thank you for the information.

ASSISTANT: Thank you for availing us.