You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I aid you?

USER: I am Richard Perez. I have planned to attend a marriage function at Dallas, help me in booking my flight ticket from CA-SFO.

ASSISTANT: Sure, can you help me with your travelling dates?

USER: My travelling dates are from 08/20 to 08/22.

ASSISTANT: Ok, may I know your destination airport code?

USER: My landing airport code is TX-DFW.

ASSISTANT: There is a direct flight with fare 100, the number 1000 in airline Hawaiian. Can I book it?

USER: Please do not proceed, I need a connecting flight. Thank you for your help.

ASSISTANT: Sorry, there is no connecting flight on your requested dates.