You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: I would like to travel from DCA to SFO as a business trip, can you do the reservation?

ASSISTANT: Please provide your travel dates.

USER: My journey dates are APR 11th and APR 13th.

ASSISTANT: Is there any specification?

USER: I need break in my journey.

ASSISTANT: Can I know your name?

USER: Scott Clark here.

ASSISTANT: Sorry, there is no flight with your travelling dates.

USER: No problem, thanks for the information.

ASSISTANT: Thank you.