You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello,. How may I be of your help?

USER: I am Donald Moore, help me to change my reservation as my plan to visit my elder sister house is postponed. Can you help me with that?

ASSISTANT: Sure, please wait.

USER: Sure.

ASSISTANT: Thanks for waiting, no reservation found with your name.

USER: Ok, thank you for the information.

ASSISTANT: Thanks for approaching us.