You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Donna Nelson here.

ASSISTANT: How can I help you today?

USER: I want to reserve my ticket from DFW to OAK, can you please help me out?

ASSISTANT: Sure Nelson, I am here to help you to book a flight. Can you please share me your travelling dates?

USER: Sure, my planned dates of travel are from 08/31 to 09/02.

ASSISTANT: Please allow me a moment to check the flight availability.

USER: Sure, I will allow it.

ASSISTANT: Sorry, no flights are available on your route.

USER: Ok, no problem. Anyways, thank you for your service.

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