You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: Myself Margaret Thompson. I just want to change my existing reservation, can you help me for that.

ASSISTANT: Sure, can you give me a moment, I will check with my database.

USER: Ok.

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

USER: Ok, that's fine. Thank you for your services.

ASSISTANT: Thank you for reaching us.