You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello, how can I assist you for the day?

USER: I am Patrick Roberts.

ASSISTANT: Ok.

USER: Can you please book a flight ticket to San Francisco with normal cost?

ASSISTANT: Sure, can you please mention your location codes?

USER: My journey codes are, HOU to SFO.

ASSISTANT: Ok. When are you willing to travel?

USER: I want to start on Jun 23rd and return on 25th afternoon.

ASSISTANT: Do you need any halt in between your journey?

USER: Yes, I need a halt in between journey.

ASSISTANT: Do you prefer any class?

USER: I am comfortable with any class.

ASSISTANT: Ok. Please wait for a while, let me check.

USER: Sure.

ASSISTANT: Sorry , no flight found.

USER: Ok, no problem.

ASSISTANT: Thank you for reaching us.

USER: Thank you.