You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Laura King.

ASSISTANT: How can I help you today?

USER: As I am a C.B.I office, I have planned to go to Boston for a special case, but due to emergency I would like to change my existing reservation. Could you please help me in changing?

ASSISTANT: Sure, I am glad to help you to change your reservation.

USER: Thank you.

ASSISTANT: Sorry, no reservation found on your name to change your reservation.

USER: Ok, not an issue. Thank you.

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