You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you at this moment?

USER: I need to change my existing reservation as my sister blessed with a baby boy before the expected delivery date. So can you please help me in that?

ASSISTANT: Sure. Please wait for a while.

USER: Sure.

ASSISTANT: Thank you for waiting. There is no reservation existing on your name. May I know your name?

USER: My name is Kevin Thomas.

ASSISTANT: Once  again I will check with your name.

USER: Ok.

ASSISTANT: Sorry, on this name there is no reservation found.

USER: I will wait. No problem, thanks for you information.

ASSISTANT: Welcome. Thank you for approaching us.