src/lay/modules/form.js
function(value, callback, origin){
            var num = 0;
            layui.each(dds, function(){
              var othis = $(this)
              ,text = othis.text()
              ,not = text.indexOf(value) === -1;
              if(value === '' || (origin === 'blur') ? value !== text : not) num++;
              origin === 'keyup' && othis[not ? 'addClass' : 'removeClass'](HIDE);
            });
            var none = num === dds.length;
            return callback(none), none;
          }
function(value, callback, origin){
            var num = 0;
            layui.each(dds, function(){
              var othis = $(this)
              ,text = othis.text()
              ,not = text.indexOf(value) === -1;
              if(value === '' || (origin === 'blur') ? value !== text : not) num++;
              origin === 'keyup' && othis[not ? 'addClass' : 'removeClass'](HIDE);
            });
            var none = num === dds.length;
            return callback(none), none;
          }
检测值是否不属于 select 项