You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. In which way I can aid you today?

USER: I want to do some changes in my existing reservation. Can you help me for that?

ASSISTANT: Sure, I will aid you with that. Could you please mention your name?

USER: My name is Karen Hill.

ASSISTANT: Ok, please hold on a moment, I will check your previous reservation status.

USER: Sure, I will wait for your response.

ASSISTANT: There is no previous reservation available under your name.

USER: That's ok, thank you for checking.

ASSISTANT: Thank you for contacting us.