You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I aid you today?

USER: I have a live music concert at Denver, please help me in booking a ticket from LAX to DEN.

ASSISTANT: I a very happy to help you in booking, can I know your preferable dates?

USER: My preferable travel dates are on Oct 27 and Oct 29.

ASSISTANT: Do you have any specifications?

USER: My budget is below 500 for this trip.

ASSISTANT: Sorry to say this, no flights are available on your desired route.

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

ASSISTANT:  May I know your name please.

USER: My name is Rachel Carter.

ASSISTANT: Thank you for contacting us.