You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: My name is Dennis Martinez. I would like to visit Houston Zoo with my friends, please help me in booking a ticket from SFO to HOU.

ASSISTANT: May I know your desired travel dates please?

USER: My planned journey dates are on Sept 30 and Oct 02.

ASSISTANT: Do you have any specifications?

USER: I would like to return in the morning.

ASSISTANT: Sorry to say, there is no flight on your desired travel dates.

USER: Ok, no problem. Thank you for your information.

ASSISTANT: Thank you for opting us.