You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I serve you at this moment?

USER: I am Brian Martin want to change my reservation owing an emergence. Can you help me in changing?

ASSISTANT: Sure, we are here to help you. May I know on which name the ticket has been reserved? Sorry, please wait for a while.

USER: Ok, I will wait.

ASSISTANT: Sorry to inform you that, we couldn't find any reservation with your name in our database.

USER: Ok, no issues. Thank you for availing me.

ASSISTANT: Thank you for reaching us.