function includeHTML() {
    var z, i, elmnt, file, xhttp;
    /*loop through a collection of all HTML elements:*/
    z = document.getElementsByTagName("*");
    for (i = 0; i < z.length; i++) {
        elmnt = z[i];
        /*search for elements with a certain atrribute:*/
        file = elmnt.getAttribute("w3-include-html");
        if (file) {
            /*make an HTTP request using the attribute value as the file name:*/
            xhttp = new XMLHttpRequest();
            xhttp.onreadystatechange = function() {
                if (this.readyState == 4) {
                    if (this.status == 200) { elmnt.innerHTML = this.responseText; }
                    if (this.status == 404) { elmnt.innerHTML = "Page not found."; }
                    /*remove the attribute, and call this function once more:*/
                    elmnt.removeAttribute("w3-include-html");
                    includeHTML();
                }
            }
            xhttp.open("GET", file, true);
            xhttp.send();
            /*exit the function:*/
            return;
        }
    }
}
(function() {
    console.log(bowser);
    if (bowser.msie && typeof Object.assign != 'function') {
        Object.assign = function(target) {
            'use strict';
            if (target == null) {
                throw new TypeError('Cannot convert undefined or null to object');
            }

            target = Object(target);
            for (var index = 1; index < arguments.length; index++) {
                var source = arguments[index];
                if (source != null) {
                    for (var key in source) {
                        if (Object.prototype.hasOwnProperty.call(source, key)) {
                            target[key] = source[key];
                        }
                    }
                }
            }
            return target;
        };
    }
    if (bowser.msie) {
        if (!Math.sign) {
            Math.sign = function(x) {
                // If x is NaN, the result is NaN.
                // If x is -0, the result is -0.
                // If x is +0, the result is +0.
                // If x is negative and not -0, the result is -1.
                // If x is positive and not +0, the result is +1.
                return ((x > 0) - (x < 0)) || +x;
                // A more aesthetical persuado-representation is shown below
                //
                // ( (x > 0) ? 0 : 1 )  // if x is negative then negative one
                //          +           // else (because you cant be both - and +)
                // ( (x < 0) ? 0 : -1 ) // if x is positive then positive one
                //         ||           // if x is 0, -0, or NaN, or not a number,
                //         +x           // Then the result will be x, (or) if x is
                //                      // not a number, then x converts to number
            };
        }
        if (!String.prototype.includes) {
            String.prototype.includes = function(search, start) {
                'use strict';
                if (typeof start !== 'number') {
                    start = 0;
                }

                if (start + search.length > this.length) {
                    return false;
                } else {
                    return this.indexOf(search, start) !== -1;
                }
            };
        }

        // See https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/includes
        // https://tc39.github.io/ecma262/#sec-array.prototype.includes
        if (!Array.prototype.includes) {
            Object.defineProperty(Array.prototype, 'includes', {
                value: function(searchElement, fromIndex) {

                    if (this == null) {
                        throw new TypeError('"this" is null or not defined');
                    }

                    // 1. Let O be ? ToObject(this value).
                    var o = Object(this);

                    // 2. Let len be ? ToLength(? Get(O, "length")).
                    var len = o.length >>> 0;

                    // 3. If len is 0, return false.
                    if (len === 0) {
                        return false;
                    }

                    // 4. Let n be ? ToInteger(fromIndex).
                    //    (If fromIndex is undefined, this step produces the value 0.)
                    var n = fromIndex | 0;

                    // 5. If n ≥ 0, then
                    //  a. Let k be n.
                    // 6. Else n < 0,
                    //  a. Let k be len + n.
                    //  b. If k < 0, let k be 0.
                    var k = Math.max(n >= 0 ? n : len - Math.abs(n), 0);

                    function sameValueZero(x, y) {
                        return x === y || (typeof x === 'number' && typeof y === 'number' && isNaN(x) && isNaN(y));
                    }

                    // 7. Repeat, while k < len
                    while (k < len) {
                        // a. Let elementK be the result of ? Get(O, ! ToString(k)).
                        // b. If SameValueZero(searchElement, elementK) is true, return true.
                        if (sameValueZero(o[k], searchElement)) {
                            return true;
                        }
                        // c. Increase k by 1. 
                        k++;
                    }

                    // 8. Return false
                    return false;
                }
            });
        }
        if (!String.prototype.endsWith) { // First, checks if it isn't implemented yet.
            String.prototype.endsWith = function(search, this_len) {
                if (this_len === undefined || this_len > this.length) {
                    this_len = this.length;
                }
                return this.substring(this_len - search.length, this_len) === search;
            };
        }
        // Add the String.format() method. Taken from somewhere on the net.
        if (!String.prototype.format) { // First, checks if it isn't implemented yet.
            String.prototype.format = function() {
                var args = arguments;
                return this.replace(/{(\d+)}/g, function(match, number) {
                    return typeof args[number] != 'undefined' ? args[number] : match;
                });
            };
        }

        //$.getScript("https://cdn.jsdelivr.net/bluebird/3.5.0/bluebird.min.js");

        /* if (!String.prototype.endsWith) {
            String.prototype.endsWith = function(searchString, position) {
                var subjectString = this.toString();
                if (typeof position !== 'number' || !isFinite(position) || Math.floor(position) !== position || position > subjectString.length) {
                    position = subjectString.length;
                }
                position -= searchString.length;
                var lastIndex = subjectString.lastIndexOf(searchString, position);
                return lastIndex !== -1 && lastIndex === position;
            };
        } */
    }


})();