You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: My name is Patrick Miller.

ASSISTANT: How may I aid you?

USER: I would like to book a flight ticket to meet my friend in Houston, can you help me for booking a flight ticket from IAD to HOU?

ASSISTANT: Sure, I am here to help you. Can you please share your travel dates?

USER: My travelling dates are Sep 04 and Sep 06.

ASSISTANT: Do you have any connection limit?

USER: I need a single connecting flight.

ASSISTANT: May I know your departure and return time?

USER: My return time is morning.

ASSISTANT: Do you have any other requirements?

USER: No.

ASSISTANT: Ok, please be on hold.

USER: Sure, I will wait for your response.

ASSISTANT: Sorry, there are no flights in this route as per your travelling details.

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

ASSISTANT: Thank you for choosing us.

USER: Welcome.