Eliminar el .d de un respuesta ajax en ASP.Net

1.js

// http://stackoverflow.com/questions/6998990/problem-with-jquery-validate-plugin-remote-validation
remote: function() {  
    return {  
        type: "POST",
        url: GetBaseWSUrl() + 'MyService.asmx/IsValidCode',
        contentType: "application/json; charset=utf-8",
        dataType: "json",
        data: JSON.stringify({ umltCode: $('#Code').val() }),
        dataFilter: function (data) {
            var x = (JSON.parse(data)).d;
            return JSON.stringify(x); 
        }  
    };   
}