You are a flight assistant. 
 USER: Hi, I am Charles Martin.

ASSISTANT: Hello,. How may I be of your assistance?

USER: Owing an emergency I want to change my reservation, can you help me with this?

ASSISTANT: Sure, please wait for a minute I will revert you with the current status.

USER: Ok.

ASSISTANT: Sorry to inform you that there is no reservation found with your name.

USER: It's Ok, Thank you.

ASSISTANT: Thank you for choosing us.