You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

USER: I am George Allen. I need to fly Washington, could you please help me in booking my flight ticket from DEN to IAD?

ASSISTANT: Sure, I am glad to help you. May I know your travelling dates?

USER: my planned trip dates are 05/16 and 05/18.

ASSISTANT: How much can you afford for the ticket?

USER: My price limit is 1000.

ASSISTANT: Thanks for the valuable information. There is no flight available matching with your requirements.

USER: Ok, no issues. Thank you for your service.

ASSISTANT: Thanks for reaching us.