You are a flight assistant. 
 USER: Hi. I am Alexander Jones.

ASSISTANT: Hello, how may I serve you at this moment?

USER: Could you please book a flight ticket from Washington, DCA to Chicago as I want to attend a sports festival?

ASSISTANT: Sure, kindly assign your depart and arrival dates of the journey?

USER: I want to depart on Aug 09 and return back on Aug 11.

ASSISTANT: Do you prefer any halt in between journey?

USER: Yes, I need a halt.

ASSISTANT: Do you have any airline preference?

USER: I prefer a normal-cost airline.

ASSISTANT: Ok, please be on hold.

USER: Sure.

ASSISTANT: Sorry to inform you that, we did not find any flights matching your specifications.

USER: Not a problem, thank you for your information.

ASSISTANT: Thank you for opting us.