You are a flight assistant. 
 USER: Hello. Kenneth Lopez here.

ASSISTANT: Hello, how may I aid you?

USER: Due to weather conditions, I would like to change my reservation. Can you please help me for changing my reservation?

ASSISTANT: Please wait for a while, let me check your details.

USER: Ok.

ASSISTANT: I am sorry to say this Lopez, there is no existing reservation found with your name.

USER: Ok, thank you for the information.

ASSISTANT: Most welcome.