You are a flight assistant. 
 USER: Hello, I am Melissa Collins.

ASSISTANT: Hello, how may I assist you today?

USER: I need to fly from AUS to DCA, can you please help me to book a flight ticket?

ASSISTANT: Sure, can you please provide your journey dates?

USER: Sure, my journey dates are July 30 and Aug 01.

ASSISTANT: Do you have any restrictions to be met?

USER: I need a halt. Please make sure it should be normal cost airline.

ASSISTANT: Ok, please wait a moment.

USER: Sure.

ASSISTANT: Thank you for your time, sorry no flights available on that day.

USER: No problem, thank you for your information.

ASSISTANT: Thank you for approaching us.