You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you?

USER: Can you help me to book a direct flight?

ASSISTANT:  Sure, We are here to help  out.

USER: Thank you.

ASSISTANT: On which name should I book the flight ticket?

USER: Please book my flight ticket under the name of Catherine Scott.

ASSISTANT:  Ok, Kindly share me your source and destination airport codes.

USER: My airport codes are DCA and AUS.

ASSISTANT: When would you like to travel?

USER: My preferable journey dates are Apr 28 and Apr 30.

ASSISTANT: Do you have any other preferences ?

USER: No, thanks for asking.

ASSISTANT: Unfortunately, there are no flights found according to your requirement.

USER: No problem, thank you for the information.

ASSISTANT: Thank you for opting us.