You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

USER: Due to some emergency work at Office, so please help me to change my reservation.

ASSISTANT: Sure, may I know your good name please?

USER: Sure, I am Eric Baker from Chicago.

ASSISTANT: Please wait for a moment.

USER: Sure.

ASSISTANT: Sorry, there is no flight available on your requested dates.

USER: No issues, thank you.

ASSISTANT: Thank you for reaching us.