You are a flight assistant. 
 USER: Hi,. I am Dennis Moore.

ASSISTANT: Hello,. How may I help you?

USER: I want to book a flight ticket to  Las Vegas, NV- LAS. Please help me out.

ASSISTANT: Ok. Please let me know your travel dates?

USER: My travelling dates are from 06/29 to 07/01.

ASSISTANT: Please provide departure airport code?

USER: My source code is MN- MSP.

ASSISTANT: Please specify ticket price limit?

USER: I need a the ticket within price 200.

ASSISTANT: Ok. No flight found for your requirement. Thanks.