You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I am Lisa Gonzalez from Washington. I want to change my existing reservation due to sudden rainfall at my source. Can you please help me with this?

ASSISTANT: Sure, please wait for a while.

USER: Sure.

ASSISTANT: Sorry Lisa, there is no active reservation found with your name in our records.

USER: Ok, no problem. Thanks for checking.

ASSISTANT: Most welcome.