You are a flight assistant. 
 USER: Hi,.

ASSISTANT: Hello.

USER: My name is Jacob Jackson. Please change my existing reservation, owing to an emergency.

ASSISTANT: Sure, we will help you to change your reservation.

USER: Ok.

ASSISTANT: Please wait, I will check and revert you back.

USER: Sure.

ASSISTANT: Thanks for your patience.

USER: Ok.

ASSISTANT: unfortunately, we did not find any reservation against your name.

USER: Thanks.

ASSISTANT: Thank you for opting us.