You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you with today?

USER: I'm Timothy Mitchell. I had planned to visit my friend's place, but it has been postponed.can you please change my existing reservation?

ASSISTANT: Sure, I can help you with that.

USER: Ok.

ASSISTANT: Please allow me a moment to check the details for you.

USER: Sure.

ASSISTANT: Timothy, I have checked and see that there is no reservation found under your name.

USER: Ok. That's not a problem.

ASSISTANT: Thank you for contacting us.

USER: Thank you for your help.

ASSISTANT: You are welcome.