You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I help you?

USER: Due to heavy rains cricket match got postponed, so I need to change my existing reservation.

ASSISTANT: Sure, give me a minute. May I know your name?

USER: I am Dennis Davis.

ASSISTANT: Sorry, there is no reservation found under your name.

USER: Ok. Thanks for your information.

ASSISTANT: Thank you for opting us.