You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you?

USER: Due to heavy rain, I want to change my reservation. Can you help me?

ASSISTANT: Sure, may I know your name?

USER: Alexander Martinez here.

ASSISTANT: Please wait a moment.

USER: Ok.

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

USER: No problem, Thank you.

ASSISTANT: Thank you for opting us.