You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I help you today?

USER: I would like to meet my elder brother in Denver, can you please help me to book my flight ticket from LAX to DEN?

ASSISTANT: Sure, I can help you with that.

USER: Thank you.

ASSISTANT: Can you please mention your travel dates for booking flight ticket?

USER: I would like to depart on 07/25 and also book the return ticket on 07/27.

ASSISTANT: May I know your name for  further process?

USER: My name is Stephen Lopez.

ASSISTANT: Ok, please hold on a moment, I will check flight availability.

USER: Sure.

ASSISTANT: Sorry for the inconvenience no flights available in this route as per your requested dates.

USER: No problem, anyway thank you for checking.

ASSISTANT: You are welcome.