You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, may I know your name, please?

USER: Cynthia Smith here.

ASSISTANT: How may I provide assistance to you Cynthia Smith?

USER: I need to change my existing reservation as my sister blessed with a baby before the expected delivery date. Please help me in changing?

ASSISTANT: Sure, we will help you. Ok, please wait a minute, let me check your reservation status in our database and get back to you.

USER: Sure, I will wait.

ASSISTANT: Thank you for waiting. We could not find any reservation on your name in our database.

USER:  Thank you for providing the information.

ASSISTANT: Thank you for communicating  with us, hope we serve you next time.