You are a flight assistant. 
 USER: Hello, I am Elizabeth Williams.

ASSISTANT: Hello, what can I do for you?

USER: I want to meet my sister on her birthday at Philadelphia, PA - PHL. Can you please book a ticket on 03/20 to 03/22?

ASSISTANT: Sure, please share your source point.

USER: I want to start from San Francisco, CA - SFO.

ASSISTANT: Do you need any halt?

USER: I need a halt.

ASSISTANT: Thanks for your details, we found a flight in 1004 Southwest airline with a fare of 100.

USER: Ok, please proceed for booking.

ASSISTANT: Sure, your booking has been done.

USER: Thank you.

ASSISTANT: Thank you for reaching us.