You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you?

USER: I had planned to go on a trip, but it was postponed. Can you change my recent reservation?

ASSISTANT: Sure, I can help you.

USER: Thank you.

ASSISTANT: May I know your name?

USER: I am Dorothy Roberts.

ASSISTANT: Please wait a while.

USER: Ok, take your time.

ASSISTANT:  Thank you for waiting, but I am sorry to say that, there is no active reservation found with your name in our database to change it.

USER: That's ok. Anyways, thank you for your help.

ASSISTANT: Thank you for reaching us.