You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello, how may I help you?

USER: I want to book a flight ticket on 08/15 to 08/17.

ASSISTANT: Ok, may I know your name?

USER: I am Debra White.

ASSISTANT: Ok  Debra, can I know your travelling airport codes please?

USER: I am planning to meet my childhood friend's in TX - AUS and my origin from TX - IAH.

ASSISTANT: That's good but sorry for inconvenience, all the flights are busy on those dates. So, there is no flight available for you.

USER: It's ok, not an issue, thank you, for your good service.

ASSISTANT: Most welcome.