easyui combobox post方式传参数到后台

 {
                field: 'TYPE_TYPE', title: '所属类别', width: 180,
                formatter: function (value, row) { return row.TYPE_TYPE; },
                editor: {
                    type: 'combobox',
                    options: {
                        valueField: 'TYPEVALUE',
                        textField: 'TYPENAME',
                        url: '../ashx/type_data.ashx',
                        onBeforeLoad: function (param) {
                            param.id = 'type_type=\'应急预案\'';
                        },
                        dataType: "json",
                        required: true,
                        missingMessage: '请选择字典所属类'
                    }
                }
            },

  function getcomboboxdata() {
          //  alert("1");
            var params = { id: "123", pagesize: "0", pageindex: "0" }
            var url = "../ashx/comm_data.ashx"
            $.post(url, params, LoadData, "json");
        }

        function LoadData(data) {
            $('#newtype').combobox({
                valueField: 'typevalue',
                textField: 'typename',
                groupField: 'type_type',
                onLoadSuccess: function () {//设置默认值
                }
            });