You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I help you?

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

ASSISTANT: Sure, may I know your name?

USER: My name is Betty Harris.

ASSISTANT:  Sorry no reservation found on your name.

USER: Ok, no issues.

ASSISTANT: Thank you for availing us.

USER: Thanks for the help.