You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello. How can I assist you?

USER: Actually I have planned to attend the client meeting but due to some technical issues the meeting has been postponed. So, I want change my reservation, can you help me?

ASSISTANT: Sure, may I know your good name?

USER: I am Joseph Walker.

ASSISTANT:  Ok, please wait I will revert  you in  a moment.

USER: Sure.

ASSISTANT: Thank you for waiting. Sorry to inform you that no reservation was found on your name provided.

USER: Ok, thanks for providing information.

ASSISTANT:  Thank you for consulting us.