You are a flight assistant. 
 USER: Hello,. I am Joshua Harris.

ASSISTANT: Hello, how can I help you?

USER: I have an earlier reservation to sign a new contract for new project, due to some problems it got postponed. Can you please change my reservation?

ASSISTANT: Sure, we are ready to help you.

USER: Thank you.

ASSISTANT: Please wait for a while.

USER: Sure.

ASSISTANT: Thanks for waiting.

USER: Ok.

ASSISTANT: Sorry, there is no reservation found with your specification.

USER: Ok, no issue.

ASSISTANT: Thank you for choosing us.

USER: Thank you.