You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, do you need any help from us?

USER: Help me to cancel my previous flight reservation. As I modified my travel dates.

ASSISTANT: Ok, could I have your name please?

USER: Donna Wilson here.

ASSISTANT: Ok, please allow me a moment.

USER: Sure.

ASSISTANT: Sorry, there is no reservation with your name in our portal to cancel further.

USER: Not an issue. Thanks for checking.

ASSISTANT: You are welcome, have a great day.