You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I serve you?

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

ASSISTANT: Sure, may I know your name?

USER: My name is Rebecca Martinez.

ASSISTANT: Please wait for a minute.

USER: Ok.

ASSISTANT: I am sorry to inform that there is no reservation found with your name.

USER: Ok, no issues. Thanks for the help.

ASSISTANT: Thank you for availing us.