nl_tokens: 展开下拉
pl_tokens: function ( ) { var thisDd = dl . children ( 'dd.' + THIS ) ; if ( ! thisDd [ 0 ] ) return ; var posTop = thisDd . <mask> ( ) . top , dlHeight = dl . height ( ) , ddHeight = thisDd . height ( ) ; //若选中元素在滚动条不可见底部 if ( posTop > dlHeight ) { dl . scrollTop ( posTop + dl . scrollTop ( ) - dlHeight + ddHeight - 5 ) ; } //若选择玄素在滚动条不可见顶部 if ( posTop < 0 ) { dl . scrollTop ( posTop + dl . scrollTop ( ) - 5 ) ; } }