You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: Myself Carol Clark. I want to change my existing reservation.Can you please help me out?

ASSISTANT: Sure, please wait for a minute.

USER: Ok.

ASSISTANT: I am sorry for your inconvenience, I cannot find any reservation with your name.

USER: Ok, thank you for your information.

ASSISTANT: Thanks for contacting us.

USER: You are welcome.