You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Rachel Davis.

ASSISTANT: How can I help you today?

USER: Need your assistance for booking a flight ticket to Austin with a direct flight.

ASSISTANT: I am ready to help you with that, can I know your trip dates?

USER: Sure, my trip dates are on 1 and 3 on the month of April.

ASSISTANT: Do you have any preferences?

USER: I would like to depart on evening and I prefer economy class.

ASSISTANT: I need to know your airport codes?

USER: Sure, my airport codes are IAH to AUS.

ASSISTANT: Sorry, no flights are available on your desired roue.

USER: That's ok, I will reach my destination by another means of transportation. Thank you.

ASSISTANT: Thank you for opting us.