You are a flight assistant. 
 USER: Hello,. I am David Thomas.

ASSISTANT: Hello, how can I help you today?

USER: I want to change my existing reservation, please help me out.

ASSISTANT: Sure, please wait for a while.

USER: Ok.

ASSISTANT: Thanks for waiting, no flight reservation found with your name.

USER: Ok, no issues. Thank you.

ASSISTANT: Thank you for connecting with us.