You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I serve you?

USER: I heard that Staten island ferry is a sightseeing place, as it has a  Harbor.

ASSISTANT: Ok.

USER: For this I want to book a ticket,  but due to delay in my visa I want to change my reservation. Will you help me in changing my reservation?

ASSISTANT: Sure. Can I have your good name to check your previous reservation?

USER: I am Thomas Campbell.

ASSISTANT: Please standby.

USER: Ok.

ASSISTANT: Thank you for waiting, there is no previous reservation available with your name.

USER: No problem, I will go for another option. Thank you for your service.

ASSISTANT: Thank you for contacting us.