You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I would like to change my flight reservation as my trip got postponed, can you please help me?

ASSISTANT: Sure, can you please help me with your name?

USER: My name is David Wilson.

ASSISTANT: Thank you. Please wait for a while, I will check your reservation status and get back to you.

USER: Please take your time.

ASSISTANT: David Wilson, I did not find any reservation under your name in our database.

USER: Very sad to hear that. Anyway, thank you for the information.

ASSISTANT: You are welcome and have a nice day.