You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I serve you?

USER: Lat week I have booked a ticket to Boston but due to heavy work load in my office, I want to alter my existing reservation. Can you please help me with that?

ASSISTANT: Sure, may I know your name?

USER: Yes, my name is Daniel Miller.

ASSISTANT: Please wait a moment, I will check and revert you.

USER: Sure, take your time.

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

USER: That's ok, may be I have done a wrong booking. I will check it once and get back to you later.

ASSISTANT: Thank you for choosing us, have a good day.

USER: Thank you for your service.