You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Barbara Collins.

ASSISTANT: How can I help you?

USER: I need to consult my family doctor in Chicago. Will you please help me in booking a ticket in flight that departs in the evening and returns in morning?

ASSISTANT: Sure, I will help you to book a flight ticket. Can you please share me your travelling dates?

USER: I would start on Feb 11th and return on 13th.

ASSISTANT: Ok, do you have any specifications?

USER: Yes, I need 1 stop over with in my journey.

ASSISTANT: Ok, may I know your travelling airport codes?

USER: My origin is IAH and destination is ORD.

ASSISTANT: Ok, may I know your arrival and departure time?

USER: I have already mentioned above.

ASSISTANT: Ok. Please allow me a moment.

USER: Sure.

ASSISTANT: Sorry, no flights are available on your route as per your requirements.

USER: That's ok, thanks for your assistance.

ASSISTANT: Welcome, have a nice day.