You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Daniel Hall here.

ASSISTANT: What can I do for you?

USER: I have changed my plans. Can you cancel my previous reservation?

ASSISTANT: Ok, please wait.

USER: Sure.

ASSISTANT: Thank you, there is no reservation has been found.

USER: No problem. Thank you for your time.

ASSISTANT: Thank you for contacting us.Have a nice day.