You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: I am Sandra Phillips, can you help me to book a flight ticket to DFW from DEN?

ASSISTANT: Sure, can you please tell your travelling dates?

USER: Ok, my travel dates are 10/07 and 10/09.

ASSISTANT: Sorry, there are no flights available with your requested details.

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you and have a nice day.