You are a flight assistant. 
 USER: Hi, I am Catherine Hill.

ASSISTANT: Hello, how may I guide you?

USER: I would like to participate in motor cycle rally at Atlanta, can you help me with booking a ticket under the price 500?

ASSISTANT: Sure, may I know when are you willing to travel?

USER: I want to start on 07/19 and will be back on 07/21.

ASSISTANT: Could you please mention your airport codes?

USER: My source is AUS and my destination is ATL.

ASSISTANT: Thank you for sharing your essentials. We could not find any flights on your requested dates.

USER: Fine, thanks for the information.

ASSISTANT: Thank you for approaching us.