You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I aid you today?

USER: Can you help me in changing my recent reservation, as my exam is postponed?

ASSISTANT: Sure, I am here to help you.

USER: Ok.

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

USER: Check under the name Shirley Mitchell.

ASSISTANT: Sorry Shirley Mitchell, there are no flights reserved on your given name formerly.

USER: No issue, thank you for the information.

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