You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I help you?

USER: I want to change my existing reservation which is done recently due to some health issues, can you please help me?

ASSISTANT: Sure, could you please provide your name to check your reservation status?

USER: Sure, my name is Lisa Edwards.

ASSISTANT: Ok, please hold on for a moment.

USER: Sure, I will wait.

ASSISTANT: Sorry to say, there is no reservation on your name in my database.

USER: Ok, that's fine. Anyways, thank you for your appreciable service.

ASSISTANT: Thank you for choosing us, have a nice day.