You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. What can I do for you?

USER: I am Lisa Rodriguez. I am planning to visit my brother's home from HOU to IAD. Can you help me out?

ASSISTANT: Sure, may I know your trip dates?

USER: My travelling dates are 06/09 to 06/11. Make sure my price limit is 200.

ASSISTANT: Sorry, no flights had been found on your details.

USER: That's fine. Thank you for your help.

ASSISTANT: Ok, thank you for reaching us.