You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I aid you?

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

ASSISTANT: Sure, can you give your name?

USER: Sure, my name is Lisa Parker.

ASSISTANT: There is no reservation found on your name.

USER: Ok, no problem.

ASSISTANT: Thank you for approaching us.

USER: Thank you for your service.