You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you today?

USER: Due to heavy rains in my home town, I want to change my reservation.

ASSISTANT: Ok.

USER: William collins here.

ASSISTANT: Please allow me a moment to check the details for you.

USER: Sure.

ASSISTANT: Your patience is greatly appreciated. William, I have checked and see that there is no reservation found under your name.

USER: It's ok. Thank you for assisting me.

ASSISTANT: Thank you for contacting us.