You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you today?

USER: I am planning to visit Millennium Park at Chicago, could you please help me with booking a flight ticket from IAD to ORD?

ASSISTANT: Sure, I am here to help you in booking. Can you please share your travel dates?

USER: I would like to depart on May 25th and return on May 27th.

ASSISTANT: Ok, may I know your name?

USER: I am Barbara Garcia.

ASSISTANT: Do you need any break in between your journey?

USER: I am looking for a connecting flight.

ASSISTANT: Do you have any specification?

USER: Make sure that my depart time must be evening and return time must be afternoon.

ASSISTANT: Sorry, no flights are available on your preferable travel dates.

USER: Ok, not an issue. Anyways, thank you for the information.

ASSISTANT: Thank you for reaching us, have  a nice day.