You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you today from my end?

USER: I want to book a direct flight to Washington, IAD to go for Music festival. Can you please help me for booking?

ASSISTANT: Sure, I am here to help you out. Please provide me your trip dates.

USER: My travelling dates are Apr 13 and Apr 15.

ASSISTANT: May I know your requirement?

USER: I prefer normal-cost airline.

ASSISTANT: Can you provide me your source airport code?

USER: My source is Houston, HOU.

ASSISTANT: May I know your respected name?

USER: Sure, I am Steven Nelson.

ASSISTANT: Sorry  Steven Nelson, there is no flight in your route.

USER: Ok, Thank you for your service.

ASSISTANT: Thank you for reaching us.