You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: I am Patrick Lopez planning to shoot my film in San Francisco, can you book a flight on dates 12/09 and 12/11?

ASSISTANT: Sure, provide me your airport codes?

USER: Yes, my airport codes are HOU and SFO.

ASSISTANT: Ok, please wait I will check the availability.

USER: Ok.

ASSISTANT: Sorry, no flights were available on your requested dates.

USER: Ok, thank you.

ASSISTANT: thank you, have a nice day.