You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I assist you?

USER: Due to heavy rain tournament got postponed, so I need to change my existing reservation.

ASSISTANT: Sure, I will help you with that. May I know your name?

USER: Helen Nelson is my name.

ASSISTANT: Ok, please wait for a moment.

USER: Ok.

ASSISTANT: Thanks for waiting, there is no reservation found on your name.

USER: That's ok, thank you for checking.

ASSISTANT: Thank you for choosing us.