You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Justin Mitchell.

ASSISTANT: How may I support you today?

USER: I am planning to travel from LGA to AUS, help me in booking a flight?

ASSISTANT: Sure, we are here to help you in booking. On which dates would you like me to book a flight ticket for you?

USER: My travelling dates are 06/17 to 06/19.

ASSISTANT: May I know if you prefer to have any other comforts in your journey?

USER: Actually I am looking for business class with single connection flight.

ASSISTANT: Thank you for sharing your journey details,  I regret to inform you that there is no flight obtained on your class preference.

USER: Proceed for booking. That's ok, thank you.

ASSISTANT: Thank you for approaching us.