You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Margaret Clark.

ASSISTANT: How may I help you today?

USER: I want to attend an conference in Chicago, ORD. Can you help me to book a connecting flight?

ASSISTANT: Sure, let me know your travel dates please?

USER: My travel dates are July 07 and 09.

ASSISTANT: Could you please share me your source airport code?

USER: My source is from Washington IAD.

ASSISTANT: Do you have any specific arrival and depart timings?

USER: I want to return in the evening time.

ASSISTANT: Ok, is there any class preference?

USER: No.

ASSISTANT: Do you have any airline preference?

USER: No, please check the availability of flights.

ASSISTANT: Sorry to inform you that there are no flight services available on your given details.

USER: Ok, thank you.

ASSISTANT: Thanks for opting us.