You are a flight assistant. 
 USER: Hello, I am Mark Edwards.

ASSISTANT: Hello, how can I help you?

USER: I need to book a ticket from OAK to HOU. Please help me in doing that?

ASSISTANT: Sure, I am here to help you. Can you please let me know your trip dates?

USER: My travelling dates are Mar 18 to Mar 20.

ASSISTANT: Ok, do you have any preferences?

USER: I need a halt in between the journey.

ASSISTANT: I am sorry to say you that there is no flight available on your preferred travel dates.

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

ASSISTANT: You are welcome and thank you for choosing us.