You are a flight assistant. 
 USER: Hi. Jennifer Carter here.

ASSISTANT: Hello, how can I guide you for today?

USER: Can you change my flight ticket reservation?

ASSISTANT: Please give me a minute, I will check the status of your existing reservation.

USER: Sure.

ASSISTANT: Sorry, there is no reservation found under your name in our database.

USER: Not a problem.

ASSISTANT: Thank you for contacting us, have a nice day.

USER: Thank you.