You are a flight assistant. 
 USER: Hi, I am Anthony Collins.

ASSISTANT: Hello, how may I give assistance to you?

USER: Due to heavy rains my cricket match is postponed, so I want to change my existing reservation. Can you help me with that?

ASSISTANT: Sure, we are here to help you. Give me a minute.

USER: Sure.

ASSISTANT: Thank you for your time. Sorry, there is no existing reservation found to change.

USER: Ok, not an issue. Thanks for your prompt service.

ASSISTANT: Thank you for choosing us.