You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello,. How may I help you?

USER: My name is Samantha Nelson. I am having a meeting with President at Washington. Can you help me in booking a ticket from DEN to DCA?

ASSISTANT: Please provide your travel dates?

USER: My preferred journey dates are 04/25 and 04/27.

ASSISTANT: Please provide price limit?

USER: It is 1000.

ASSISTANT: No flights found for your requirement.

USER: Its ok, thank you for the information.

ASSISTANT: Thank you.