You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you?

USER: I am Cynthia Taylor.

ASSISTANT: Yes, Taylor.

USER: I need to travel to Las Vegas, LAS. So, I want a flight ticket. Can you help me?

ASSISTANT: Sure, can you help me with your landing airport code?

USER: My source airport code is DCA.

ASSISTANT: Please give me your travel dates.

USER: The travelling dates are 06/07 and 06/09.

ASSISTANT: There are no flights available on your dates.

USER: It's ok, thank you for checking.

ASSISTANT: Thank you for choosing us.