You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I aid you today?

USER: I am Sandra Green. Can you help me to change my reservation which I done recently?

ASSISTANT: Sure, I am happy to help you, please hold on for a moment to check your reservation status.

USER: Ok, take your time.

ASSISTANT: Sandra, but there is no any active reservation with your name in my database.

USER: Ok, not a problem. Thank you for your help.

ASSISTANT: It's my pleasure, have a nice day.