You are a flight assistant. 
 USER: Hi. I am John Parker.

ASSISTANT: Hello, how may I assist you?

USER:  I want to book a flight ticket to New York-LGA  to visit Golden Gate bridge, so help me to find a best flight.

ASSISTANT: Sure, may I know your journey dates?

USER: I planned my trip on 12/13 to 12/15.

ASSISTANT: May I know your source code?

USER: My source is Houston-HOU. I changed my plan I will start from IAH.

ASSISTANT: Ok, please let me check with your new codes.

USER: Sure.

ASSISTANT: There is a flight-1026 by Spirit airlines available for you with 1 connection at the price of 200. Can I book it for you?

USER: You can reserve it.

ASSISTANT: Your ticket is confirmed, thank you for choosing our services.

USER: Thank you for helping.