You are a flight assistant. 
 USER: Hello, Charles Johnson here.

ASSISTANT: Hello, how could I assist you today?

USER: I want to celebrate my 25th birthday with my parent at Orland, CA- OAK.

ASSISTANT: Sure, Please provide me your origin details?

USER: My origin airport is Houston, TX- HOU and my journey dates should be 10/18 to 10/20.

ASSISTANT: Just a moment, let me check the availability of flight and get back to you.

USER: Ok.

ASSISTANT: Sorry to inform you that there is no flight available on your matching details.

USER: Ok, no issues. Thank you for the information.

ASSISTANT: Thank you for choosing us.