//JQuery EasyUI 动态改变表单项的验证规则$(document).ready(function(){    $('#FILE_QUALITY').combobox({        onChange:function(newValue,oldValue){            if(newValue == 2){                $('#FRONT_FOR_UNIT').validatebox({                    required: false                });            } else if(newValue == 0){                $('#FRONT_FOR_UNIT').validatebox({                    required: true,                     validType: 'length[1,512]'                });            }            $.parser.parse($("#FRONT_FOR_UNIT"));        }    });});