You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: In Houston, I have some urgent work. Can you please help me in ticket booking from IAD?

ASSISTANT: Sure, may I know your trip dates please?

USER: My trip dates are from 05/27 to 05/29.

ASSISTANT: Can I know your destination airport code please?

USER: My destination airport code is IAH.

ASSISTANT: Do you have any other requirements?

USER: I want a single connecting flight in the normal cost airlines.

ASSISTANT: Can I know your name?

USER: Myself Laura Lee.

ASSISTANT: Sorry, we regret to inform you that there is no flight available as per your request.

USER: It's ok, thank you.

ASSISTANT: Most welcome.