You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Sandra Lopez here.

ASSISTANT: How may I help you?

USER: My interview got postponed, so I want to change my reservation. Could you help me out?

ASSISTANT: Sure, I will help you. Please wait a moment.

USER: Sure.

ASSISTANT: Sandra, no reservation has been found on your name in our database.

USER: It's ok, thank you for the information.

ASSISTANT: Thank you for approaching us.