You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: My name is Kathleen Harris. I want to do some modification in my existing reservation, can you please help me for that?

ASSISTANT: Sure, please give me a moment.

USER: Ok, take your time.

ASSISTANT: Sorry, no ticket is showing under your name.

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

ASSISTANT: Thank you for approaching us.

USER: Welcome.