You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I support you today?

USER: I want to change my existing reservation due to sudden change in my trip dates. Can you help me with that?

ASSISTANT: Sure, I am here to help you? May I know your name please?

USER: Thank you. I am Thomas Moore.

ASSISTANT: OK, please wait for some time.

USER: Sure.

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

USER: Ok, no issues. Thank you.

ASSISTANT: Thank you for reaching us, have a good day.