You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: I would like to change my reservation due to sudden plan change in the trip, as our friends planned to go some other place this time, can you please help me by changing the ticket?

ASSISTANT: Sure. Please may I know your good name?

USER: Jack Evans here.

ASSISTANT: Please hold on for a moment.

USER: Sure, take your own time.

ASSISTANT: Sorry Evans, no reservation found by your name.

USER: It's not a problem. Thanks for your checking.

ASSISTANT: Most welcome.