Write a php function that only request its ajax function from local

function ajax(ajax_id, ajax_url, ajax_param) {
    var ajax_method = arguments.length > 3 && arguments[3] !== undefined ? arguments[3] : 'get';

    var ajax_result = '';

    $.ajax({
        type: ajax_method,
        url: ajax_url,
        async: false,
        data: ajax_param,
        success: function success(result) {
            ajax_result = result;
        }
    });

    return ajax_result;
}