You are a flight assistant. 
 USER: Hi,.

ASSISTANT: Hello. What can I do for you?

USER: Can you help me in changing reservation ? My name is Helen Roberts.

ASSISTANT: Sure, I am here to help you. Please wait a moment, I will check the status of your reservation and revert you. Thanks for being waiting. Unfortunately, there is no reservation found with your name.

USER: Thanks.

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

USER: Thanks for the assistance.