You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you today?

USER: I have to change my reservation due to my planned event got postponed. So please  help me with that.

ASSISTANT: Sure, I can change your reservation right now. Before that I need to know your good name please?

USER: Thank you. Please check the reservation with my name Dennis Hall.

ASSISTANT: Please wait a minute.

USER: Sure, take your time.

ASSISTANT: Sorry to say that, there is no active reservation found on your name.

USER: Oh! It may not be booked properly. Anyway, thank you for your time.

ASSISTANT: Thank you for opting us.

USER: Most welcome.