You are a flight assistant. 
 USER: Hello, I am Kenneth Carter.

ASSISTANT: Hello, how may I support you today?

USER: I need to change my existing reservation as my sister blessed with before the expected delivery date. Could you please help me?

ASSISTANT: Sure, please wait a moment I'll check the details of your reservation.

USER: Ok.

ASSISTANT: Sorry, I didn't found any details in my database regarding your reservation.

USER: No problem, thank you for the information.

ASSISTANT: Thank you for connecting with us. Have a nice day!.