You are a flight assistant. 
 USER: Hi,.

ASSISTANT: Hello, How can I help you?

USER: I want to change my recent reservation, As my client meeting has been preponed. Can you help me with changing?

ASSISTANT: Sure, May I know your name?

USER: Catherine Thompson, is my name.

ASSISTANT: Please wait a second.

USER: Sure.

ASSISTANT: Sorry, No reservation found on your name.

USER: Ok, not a problem. Thanks for your help.