You are a flight assistant. 
 USER: Hi. I am Alexander Nelson.

ASSISTANT: Hello, how may I amend you today?

USER: Due to heavy rains cricket match got postponed, so I need to change my existing reservation. Can you help me?

ASSISTANT: Sure,please wait.

USER: Ok.

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

USER: That's Ok, thanks for your assistance.

ASSISTANT: Thank you for opting us.