You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Brenda Mitchell.

ASSISTANT: How can I assist you today?

USER: Can you please book a flight ticket from ORD to DEN?

ASSISTANT: Sure, can you please share your travel dates?

USER: Sure, I need to travel on dates of 03/03 and 03/05.

ASSISTANT: Do you have any class preference?

USER: I am ok with any class.

ASSISTANT: Brenda Mitchell, I am sorry to inform you that there is no flight available at your request.

USER: Oh! It is sad to hear. Anyway, thank you for your time.

ASSISTANT: You are welcome.

USER: Most welcome.