You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Lisa Adams.

ASSISTANT: How can I help you, Lisa Adams?

USER: I need to book a flight ticket because I have planned to visit a comic show on 08/05 and I want to return on 08/07, can you help me in booking flight ticket?

ASSISTANT: May I know your airport codes, Please?

USER: My airport codes are: SFO and DFW.

ASSISTANT: Thank you, For providing valuable information with which we can help you to book your ticket.

USER: My pleasure. I need a direct flight with price 500.

ASSISTANT: May I know, What is your origin airport code?

USER: SFO is my origin.

ASSISTANT: OK. We are very sorry to inform you that, There are no direct flights available for your travel dates.

USER: Ok, not an issue.

ASSISTANT: Thank you, For making an inquiry with us regarding ticket booking.

USER: Thank you for your quick information.

ASSISTANT: Have a great day.