You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I help you for today?

USER: Owing an emergence, I want to change my existing reservation. Can you please help me with it?

ASSISTANT: Ok, please mention your name to check with your previous reservation.

USER: My name is Emily Miller.

ASSISTANT: Give me a minute to check for your previous booking.

USER: Ok.

ASSISTANT: Emily Miller, no reservation was found under your name. Sorry for the inconvenience.

USER: Ok, no issues. Thanks for the help.

ASSISTANT: Have a great day Emily.