You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Mark Robinson here, I want to reserve my ticket from AUS to IAD, can you please help me to book a ticket?

ASSISTANT: How may I assist you for the day? Ok, may I know your travelling dates?

USER: Sure, my preferable dates of journey is from 05/12 to 05/14.

ASSISTANT: Mark Robinson, please hold on for a moment till I check for the availability.

USER: Sure, but please make sure that the price limit is 500.

ASSISTANT: Ok. Flight-1016 is available for you with 1 connection at the cost of 1100.

USER: Ok, please book it.

ASSISTANT: No flights available at 500.

USER: Ok, no problem.

ASSISTANT: Sorry for the inconvenience.

USER: Thank you for your appreciable service.

ASSISTANT: Have a great day ahead.