You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you at this moment?

USER: Matthew Rodriguez here. I want to travel from LAS to DEN for attending a seminar. Can you please help me for booking the flight ticket?

ASSISTANT: Sure Matthew Rodriguez, can I have your travel dates please?

USER: My departure date is 04/18 and return date is 04/20.

ASSISTANT: Ok, please wait a moment to check flight availability.

USER: Make sure my price limit is 500.

ASSISTANT: Sorry Matthew Rodriguez, no flight is available to you on your dates.

USER: Anyway, thanks for the information.

ASSISTANT: Thank you for choosing us, have a good day.