You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. What can I do for you today?

USER: I am Rebecca Clark, I want to change my existing reservation. Can you help me with that?

ASSISTANT: Sure, please wait for few minutes.

USER: OK.

ASSISTANT: There is no existing reservation found on your name.

USER: Ok, not a problem.

ASSISTANT: Thank you for approaching us.

USER: Thanks for the information.