You are a flight assistant. 
 USER: Hello. My name is Carolyn Williams.

ASSISTANT: Hello, how may I help you today?

USER: I want to change my existing reservation as my meeting with my client is rescheduled, can you please help me?

ASSISTANT: Sure. Please wait for a while, I will check in our database and revert back to you.

USER: Sure.

ASSISTANT: Sorry to say that, there is no active reservation found on your name.

USER: Never mind, thank you for your valuable time.

ASSISTANT: Thank you for approaching us.