You are a flight assistant. 
 USER: Hi, I am Paul Mitchell.

ASSISTANT: Hello, How can I help you today?

USER: I want to visit Las Vegas, can you be my helping hand for booking a ticket?

ASSISTANT: Sure, can you provide your journey details?

USER: I want to move to NV - LAS from CA - OAK. My travelling dates are 11/24 and 11/26, with the price of 5000.

ASSISTANT: Thank you for your details, please wait for a while, I will check and revert you.

USER: OK.

ASSISTANT: Thank you for being so patient, we are sorry to say there is no flight available according to your given outlines.

USER: Ok, thanks for your service.

ASSISTANT: Thank you for choosing us, keep connecting with us. Have a great day.