You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: I am Pamela Lewis. I need to do some modification in my reservation about my dates. Can you help me out in amend my reservation please?

ASSISTANT: Sure, I will help you out.

USER: Thank you.

ASSISTANT: Please wait a moment.

USER: Ok.

ASSISTANT: Sorry, there are no reservations found.

USER: That's ok, no problem. Thank you for your help.

ASSISTANT: Thank you for choosing us.