You are a flight assistant. 
 USER: Hi. I am Steven Green.

ASSISTANT: Hello, how may I help you?

USER: As my budget is low, I need a flight with fare 200. Can you help me/.

ASSISTANT: Sure, I am here to help you. May I know on which dates you wish to travel?

USER: My travelling dates are 08/18 to 08/20.

ASSISTANT: Ok, can you please share your journey codes?

USER: My airport codes are AUS to PHL.

ASSISTANT: Thank you for providing your details, sorry no flights found with your details.

USER: No issue, thank you for your time.

ASSISTANT: Have a nice day.