You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I help you for this day?

USER: Alexander Hernandez here.

ASSISTANT: Ok.

USER: I want to change my existing reservation, due to heavy rains. Could you please help me?

ASSISTANT: sorry, no flights found on your name to change the existing reservation.

USER: Thank you for the information.

ASSISTANT: You are welcome.