$scope.convertMd5 = function (string) { // retorna string em md5
        var sl;
        $http({
            method: 'POST',
            url: '../assets/php/client/Users.php',
            data: {ref: 'convert-md5', str: string},
            dataType: 'html',
        }).success(function (data) {
            sl = data;
            return sl;
        });
    }