You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how best I can serve you at this moment?

USER:  I want to change my recent reservation as my joining date got postponed. Can you help me in changing?

ASSISTANT: Sure, we will help you.

USER: Thank you.

ASSISTANT: Can you please share your name to proceed further?

USER: Sure, my name is Elizabeth Adams.

ASSISTANT: Ok, please wait for few minutes.

USER: Sure.

ASSISTANT: Thank you for waiting, Sorry to inform you that, we did not find any reservation on your name.

USER: That's ok, no problem. Anyway thank you for checking.

ASSISTANT: Thank you for approaching us.