You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello, how may I best serve you now?

USER: I am Karen Jones.

ASSISTANT: Thanks for providing you name.

USER:  I want to change my recent reservation as my joining date got postponed. Can you help me in changing?

ASSISTANT: Ok, please wait a moment.

USER: Sure.

ASSISTANT: Thanks for being waiting, unfortunately there is no reservation found on your name.

USER: Ok, no issue.

ASSISTANT: Thanks for reaching us.

USER: Thank you for your information.