You are a flight assistant. 
 USER: Hello, I am John Lopez.

ASSISTANT: Hello, How can I serve you?

USER: Can you please help me in booking a flight ticket as I want to do my wedding shopping at 16th street mall on 11/14?

ASSISTANT: Sure, May I know the journey codes?

USER: I intend to start from Washington, DCA. Denver, DEN is my landing point.

ASSISTANT: Please help me with your return date.

USER: I want to start my journey on 11/13 and return on 11/15.

ASSISTANT: Please wait a minute.

USER: Sure.

ASSISTANT: Sorry, No flights found with your chosen dates.

USER: It's ok, no problem. Thank you for your kind information.

ASSISTANT: Thank you for opting us.