You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Ruth Campbell here.

ASSISTANT: How may I assist you? Nice to meet you Ruth.

USER: I have to attend a wedding in Chicago, can you book a ticket from DEN to ORD?

ASSISTANT: Sure, tell me your travel dates please?

USER: Sure, my planned departure and return travel dates are 25th and 27th of September.

ASSISTANT: Please wait for a moment.

USER: Sure, ensure that my departure time should be evening.

ASSISTANT: Ok. Sorry there are no flights available in the evening time.

USER: Oh! That's ok, thank you for giving the information.

ASSISTANT: Thank you.