You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello,.

USER: I am Matthew Williams.

ASSISTANT: How may I aid you?

USER: I need a direct flight to go for Rainey street walk along with my loved one.Can you reserve me a flight ticket to Austin, AUS?

ASSISTANT: Sure, I am happy to help you.

USER: Thank you.

ASSISTANT: Could you please mention your preferred travel dates?

USER: My preferable dates of journey is 11/15 to 11/17.

ASSISTANT: May I know your source airport code?

USER: I want to board from Denver, DEN as it is my nearest airport.

ASSISTANT: How much is your budget for this trip?

USER: I can afford up to 500.

ASSISTANT: Please wait for a second, I will revert to you.

USER: Ok.

ASSISTANT: I am sorry to inform you that, no flights are running at your particular locations.

USER: It's ok, no problem. Thank you for your information.

ASSISTANT: Thanks for opting us.