You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, How exactly I can serve you the best today?

USER: I want to change my existing reservation due sudden postpone of my my family trip dates. Can you help me in doing that?

ASSISTANT: Sure, may I know your good name please to track the details?

USER: Sure, Kevin Clark here.

ASSISTANT: Ok, please wait for a while.

USER: Sure.

ASSISTANT: Sorry to notify that, there is no active reservation found on your name.

USER: Ok, no problem. Thank you.

ASSISTANT: Thanks for connecting us, have a nice day.