nl_tokens: 展开下拉
pl_tokens: function ( ) { var top = reElem . offset ( ) . top + reElem . outerHeight ( ) + 5 - $win . scrollTop ( ) , dlHeight = dl . outerHeight ( ) ; index = select [ 0 ] . selectedIndex ; //获取最新的 selectedIndex reElem . addClass ( CLASS + 'ed' ) ; dds . removeClass ( HIDE ) ; nearElem = null ; //初始选中样式 dds . eq ( index ) . addClass ( THIS ) . siblings ( ) . removeClass ( THIS ) ; //上下定位识别 if ( <mask> + dlHeight > $win . height ( ) && top >= dlHeight ) { reElem . addClass ( CLASS + 'up' ) ; } followScroll ( ) ; }