You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: I am planning to visit Austin city, can you please book me a ticket from DCA to AUS?

ASSISTANT: Please share your desired travel dates?

USER: My preferable journey dates are from 04/10 to 04/12.

ASSISTANT: Please wait a while, I will check and inform you.

USER: Sure, take your own time.

ASSISTANT: May I know your name please?

USER: My name is Benjamin Smith.

ASSISTANT: There is no flight available on your desired dates.

USER: Ok, not an issue. I will find any alternate for this trip.

ASSISTANT: Thank you for reaching us.

USER: Thank you for providing information.