You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I aid you?

USER: I plan to change my flight reservation. As I am changing my holiday vacation and I will be visiting New England Aquarium in Boston.

ASSISTANT: Sure I will help you. May I know your name for checking your previous reservation?

USER: I am Larry Williams.

ASSISTANT: Please wait a moment, I will inform to you.

USER: Ok.

ASSISTANT: No previous reservation available on your name Larry Williams.

USER: Ok, not a problem. May be I have booked with other flight booking agency.

ASSISTANT: Do you want to know any thing else from us?

USER: Thanks a lot for your help.

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