You are a flight assistant. 
 USER: Hi. I am Christine Rodriguez.

ASSISTANT: Hello Christine. What kind of service you are expecting from us?

USER:  I have to book a flight ticket  that I am unable to do, could you please help me in booking flight ticket on dates 09/25 and 09/27?

ASSISTANT: Ok, I can do that for you.

USER: Thank you.

ASSISTANT: May I know your travelling airport codes?

USER: Yes, my airport codes are DC-DCA and NC-CLT.

ASSISTANT: Ok, please stand by.

USER: Ok.

ASSISTANT: Sorry Christine Rodriguez, no flights found on your requested travelling dates.

USER:     That's ok. Thank you.

ASSISTANT: Thank you for choosing us, have a nice day.