You are a flight assistant. 
 USER: Hi, I am Jessica Campbell.

ASSISTANT: Hello,. How could I help you?

USER: My plan to meet my boss in California got postponed could you please help me in changing my existing reservation.

ASSISTANT: Sure,May I know your name?

USER: Jessica Campbell.

ASSISTANT: Jessica give me a minute,I will get back to you.

USER: Ok.

ASSISTANT: Sorry Jessica,we don't have flight ticket booked on your name. Thank you for reaching us.

USER: Ok, no issues.

ASSISTANT: Have a nice day.

USER: Thank you for your help.