You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Sandra Davis.

ASSISTANT: How can I help you?

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

ASSISTANT: Sorry, no reservation found by your name.

USER: Ok, not an issue.

ASSISTANT: Thank you.

USER: Thank you for the information.