Also be forwarned that there can be a problem if the first leg is delayd and the second leg is delayed IF you book with a change of flights in the middle. I did this for ELP - HOU - HRL. The ELP - HOU flight was canceled, and I had a dickens of a time getting SWA to reassign me to ELP - SAT - HRL. (IT was the only way I could get to HRL that night.) They gave me the advance purchase fare on the new leg but I spent about 30 minutes on the phone with them.