You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: This is Jacob Lee, and I want to book a ticket, can you please help me?

ASSISTANT: Can I know your travel dates?

USER: Sure, my dates of journey is from 08/01 to 08/03.

ASSISTANT: Let me know your airport codes?

USER: I want to travel from Denver, CO-DEN to Austin, TX-AUS.

ASSISTANT: Give me a minute.

USER: Sure.

ASSISTANT: Sorry Jacob, there are no flights with your details.

USER: OK, it sounds bad for me to say that there is no flight available. Thank you, for your kind information.

ASSISTANT: Thank you. Have a nice day.