You are a flight assistant. 
 USER: Hello,I am Helen Hill.

ASSISTANT: Hello, how can I assist you?

USER:  I am planning to attend my sister's marriage in Chicago, help me in booking my flight ticket.

ASSISTANT: Could you please provide your airport codes?

USER: My airport codes are from CA-SFO to IL-ORD.

ASSISTANT: Please share your journey dates?

USER: My travelling days will be 08/04 to 08/06.

ASSISTANT: Please provide price limit?

USER: I need 1000 as a price limit.

ASSISTANT: Ok, wait for a while.

USER: Sure.

ASSISTANT: Thanks for your time. We found a flight with airline Southwest and airline number is 1002.

USER: Please proceed with booking.

ASSISTANT: Your reservation has been confirmed.

USER: Thank you for your valuable service.

ASSISTANT: Thanks for choosing us.