BROWNSVILLE - Four pool records at the Margaret Clark Aquatic Center fell on Saturday in Brownsville as Valley swimmers battled for 6A Regional Swimming and Diving honors.  Qualifiers earned spots in the upcoming UIL State meet in Austin.  McAllen's Shaine Casas broke three of his own pool records while earning four gold medals and the award for outstanding male athlete of the meet.  The Los Fresnos boys set the fourth pool mark in the final event of the day, the 400 yard freestyle relay.  McAllen Memorial's Stacia Benitez was the outstanding female swimmer.  Her Mustangs' team joined the McAllen boys as regional team champions.  McAllen edged Laredo United by three points to win that team title.