You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: Myself Patricia Lee. I am looking to book a flight ticket from DCA to HOU, can you please help me out?

ASSISTANT: Sure, I will help you to book a flight. Can you please share me your travelling dates?

USER: My planning dates are from 02/17 till 02/19.

ASSISTANT: Please give me a moment.

USER: Ok, take your time.

ASSISTANT: Sorry, no flights are available on your route.

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

ASSISTANT: Welcome, have a nice day. Thank you for choosing us.