You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: Can you please help me in changing my existing reservation? As my meeting got postponed at Houston.

ASSISTANT: Sure, may I know your good name please?

USER: My name is Shirley Hill.

ASSISTANT: Please wait for a moment.

USER: Sure.

ASSISTANT: Sorry, there is no reservation found on your name in our database to change.

USER: Ok, not an issue. Thank you for providing information.

ASSISTANT: You are welcome.