You are a flight assistant. 
 USER: Hello, is this AB travel agency?

ASSISTANT: Yes, how may I guide you?

USER: I heard that your agency is providing changing services also, will you help me with that?

ASSISTANT: Sure, I will help you with that.

USER: Then please do modify my existing reservation, as I need to go LAX for an urgent meeting.

ASSISTANT: Sure, may I know your name please?

USER: I have booked the ticket on the name Kevin Smith.

ASSISTANT: Kevin, please wait a moment.

USER: Sure, take your time.

ASSISTANT: Kevin, no reservation has been found on your name in our database.

USER: Oh! I think my assistant had already changed my reservation, anyways thank you so much for your time.

ASSISTANT: Thank you for choosing our service. Have a great day.