You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. What kind of service that you are looking for?

USER: I had booked a ticket to travel Houston on my business trip but, the meeting got postponed, can you please help me to modify my booking?

ASSISTANT: Yes, I can help you with that.

USER: Thank you.

ASSISTANT: May I know on which name the ticket was booked?

USER: The ticket is booked on my name William Moore.

ASSISTANT: Ok William, please wait for a while so that I can check the status of your existing reservation.

USER: Sure.

ASSISTANT: Sorry, I could not find any flight ticket booked with your name.

USER: It's alright, thank you for  your help.

ASSISTANT: Thank you, have a good day.