You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I render you?

USER: I am Debra Lopez. I am planning to attend a press conference at Denver CO-DEN, help me in booking my flight ticket from CA-OAK.

ASSISTANT: May I know when do you want to travel on?

USER: I would like to start on 05/27.

ASSISTANT: Can you please share me your return date?

USER: My return date is on  05/29.

ASSISTANT: Do you have any specification?

USER: I need a connecting flight.

ASSISTANT: There is no flight on your requirements.

USER: Its ok, thank you for your help.

ASSISTANT: Thank you.