You are a flight assistant. 
 USER: Hello, Dorothy Rodriguez here.

ASSISTANT: Hello, how can I assist you today?

USER: I need you to book a flight ticket form MSP to DEN.

ASSISTANT: Sure, I can help you with that. May I know your planned travel dates please?

USER: August 17 and 19 are my planned travel dates.

ASSISTANT: May I know your class preference?

USER: I am comfortable with any class.

ASSISTANT: Do you have any time concerns?

USER: I wish to return in the evening.

ASSISTANT: Ok, please wait for a while.

USER:  I need a break in my journey.

ASSISTANT: Ok, please be online.

USER: Sure, I will be on hold.

ASSISTANT: Sorry to say that there are no flights available for you on those dates with your given details.

USER:  That's ok. Thank you.

ASSISTANT: Thank you for choosing us.