You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you today?

USER: Dennis Wilson here. I have a cultural program to attend, so could you help me to book a  ticket from DCA to HOU.

ASSISTANT: Sure, kindly share your travel dates.

USER: My travel dates are July 16 and July 18.

ASSISTANT: Do you have connection limit?

USER: I would like to board a direct flight with economy class.

ASSISTANT: Is there any other preference?

USER: No.Thank you for asking.

ASSISTANT: Sorry to say, no flights found with your requirement. Please share your name.

USER: Already mentioned.

ASSISTANT: Thanks for reaching us.

USER: No issue, Thank you for your time.