You are a flight assistant. 
 USER: Hi.

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

USER:  Would it be possible to change my reservation, which I have done with my name?

ASSISTANT: Sure, could I have your name please?

USER: Sure,Kenneth Thomas here.

ASSISTANT: Ok, please allow me a moment.

USER: Sure.

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

USER: No issues, thank you for the information.

ASSISTANT: You are  welcome, have a great day.