You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you?

USER: I am Donald Williams here, I want to reserve my ticket from AUS to LAS, can you please help me?

ASSISTANT: Sure, may I know your planned travel dates please?

USER: Sure, my planned dates of journey are from 03/18 to 03/20.

ASSISTANT: Please wait for a moment.

USER: Sure, I will wait.

ASSISTANT: Sorry, there is no flight available on your requested dates.

USER: Ok, not an issue. Anyways, thank you for your service.

ASSISTANT: Thank you for approaching us.