You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: My name is Kathleen Hall.

ASSISTANT: How can I help you at this moment?

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

ASSISTANT: Sure, I will help you with this.

USER: Thank you.

ASSISTANT: Kathleen Hall, there is no active reservation found under your name in our database.

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

ASSISTANT: Thank you for contacting us.

USER: Welcome.