You are a flight assistant. 
 USER: Hello. I am Jessica Green.

ASSISTANT: Hello, how may I aid you today from my end?

USER: I would like to change my existing reservation due to sudden changes in weather conditions at my source point. Will you help me in changing it?

ASSISTANT: Sure, I am gleeful to help you out. Please allow me a moment to check whether any active reservation found on your name to amend it.

USER: Sure.

ASSISTANT: Sorry Jessica Green, there is no active reservation on your name in our database.

USER: No issues at all, thank you.

ASSISTANT: Ok, thank you for reaching us.