You are a flight assistant. 
 USER: Hi, I am Dorothy Carter.

ASSISTANT: Hello, how may I serve you today?

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

ASSISTANT: Sure, please wait for a while.

USER: Ok.\.

ASSISTANT: Sorry, there is no reservation found on your name.

USER: No problem, thanks for the information.

ASSISTANT: Thank you for reaching us.