You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I oblige you today?

USER: I am Helen Clark. I have to change my previous flight ticket booking, can you please help me in that?

ASSISTANT: Sure, please wait for a moment.

USER: Thank you for considering my request in positive manner and I can wait for your reply.

ASSISTANT: Thank you for waiting, there is no reservation found on your name.

USER: Ok, that's fine.No problem with that one. Thank you for your search and providing the information.

ASSISTANT: Thank you.

USER: Welcome.