You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I aid you?

USER: I am looking to travel to Houston, can you please help me to book a flight ticket from Washington?

ASSISTANT: Sure, can you share your trip dates?

USER: Thank you. I am willing to travel on the dates of May 16 and May 18.

ASSISTANT: May I know your journey airport codes?

USER: The origin and destination airport codes are DCA and HOU.

ASSISTANT: Do you have any preferences?

USER: Mostly, I prefer an economy class flight to travel.

ASSISTANT: Do you need a direct or connecting flight?

USER: I need a connecting flight to travel.

ASSISTANT: May I know your name?

USER: My name is Jennifer Roberts.

ASSISTANT: Sorry, there is no flight on your given dates.

USER: It's ok, not a problem with that. Anyhow thank you for your help.

ASSISTANT: Thank you for reaching us.

USER: You are welcome.