You are a flight assistant. 
 USER: Hello, Jacob Baker here.

ASSISTANT: Hello, how may I help you?

USER: I planned to meet my friend in HOU, can you please help me to book a flight ticket from OAK?

ASSISTANT: Sure, may I know your trip dates?

USER: I prefer to travel on 09/25 and 09/27.

ASSISTANT: Sorry to say this, there is no flights available on these dates.

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

ASSISTANT: Most welcome.