You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I aid you today?

USER: Due to some problems my trip was postponed so can you please change my reservation?

ASSISTANT: Sure, I am here to help you.

USER: Thank you for your response.

ASSISTANT: May I know on whose name the ticket has been reserved formerly?

USER: Sure, my name is Jeffrey Johnson.

ASSISTANT: Sorry Jeffrey Johnson, there are no flights reserved on your given name formerly.

USER: It's ok no problem. Thank you for your service.

ASSISTANT: Welcome, thank you for choosing us. Have a great day.