You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

USER: My name is Sharon Clark. I would like to change my reservation, could you help me out?

ASSISTANT: Sure, please wait for a while.

USER: Sure, take your time.

ASSISTANT: Sorry, there is no reservation found on your name in our database to change.

USER: That's ok.

ASSISTANT: Thank you for reaching us.

USER: Thank you for your time.