You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you today?

USER: I would like to book a flight in normal-cost airline, so please assist me in booking a flight.

ASSISTANT: Sure, may I know your name please?

USER: Sure, my name is Laura Walker.

ASSISTANT: Please share your source and destination airports codes?

USER: My airport codes are DCA - HOU.

ASSISTANT: Ok, may I know your travelling dates please?

USER: My planned dates are on May 29th to 31st.

ASSISTANT: Is there any specific class preference for you?

USER: No.

ASSISTANT: Do you have any other specifications please?

USER: No, I don't have any other specifications.

ASSISTANT: Please wait for a moment.

USER: Sure.

ASSISTANT: Sorry Walker, there is no flight found as per your travelling details.

USER: No worries, thank you.

ASSISTANT: Thank you for opting us.