function load_home() {
     document.getElementById("content").innerHTML='';
}

<div id="topBar">
    <a href ="#" id="load_home"> HOME </a>
</div>
<div id ="content">        
</div>

<script>
$(document).ready( function() {
    $("#load_home").on("click", function() {
        $("#content").load("content.html");
    });
});
</script>

function load_home (e) {
    (e || window.event).preventDefault();

    fetch("http://www.yoursite.com/home.html" /*, options */)
    .then((response) => response.text())
    .then((html) => {
        document.getElementById("content").innerHTML = html;
    })
    .catch((error) => {
        console.warn(error);
    });
} 

function load_home (e) {
  (e || window.event).preventDefault();
  var con = document.getElementById('content')
  ,   xhr = new XMLHttpRequest();

  xhr.onreadystatechange = function (e) { 
    if (xhr.readyState == 4 && xhr.status == 200) {
      con.innerHTML = xhr.responseText;
    }
  }

  xhr.open("GET", "http://www.yoursite.com/home.html", true);
  xhr.setRequestHeader('Content-type', 'text/html');
  xhr.send();
}

    <script src="https://code.jquery.com/jquery-2.1.4.min.js"></script>


    <div id="content"></div>
    <script>
        /**
        * Test harness to find out the best method for dynamically loading a
        * html page into your app.
        */
        var test_times  = {};
        var test_page   = 'testpage.htm';
        var content_div = document.getElementById('content');

        // TEST 1 = use jQuery to load in testpage.htm and time it.
        /*
        function test_()
        {
            var start = new Date().getTime();
            $(content_div).load(test_page, function() {
                alert(new Date().getTime() - start);
            });
        }

        // 1044
        */

        // TEST 2 = use  to load in testpage.htm and time it.
        /*
        function test_()
        {
            start = new Date().getTime();
            content_div.innerHTML = ''
        }

        //1579
        */

        // TEST 3 = use httpObject to load in testpage.htm and time it.
       function test_()
       {
           var xmlHttp = new XMLHttpRequest();

           xmlHttp.onreadystatechange = function() {
                if (xmlHttp.readyState == 4 && xmlHttp.status == 200)
                {
                   content_div.innerHTML = xmlHttp.responseText;
                   alert(new Date().getTime() - start);
                }
            };

            start = new Date().getTime();

            xmlHttp.open("GET", test_page, true); // true for asynchronous
            xmlHttp.send(null);

            // 1039
        }

        // Main - run tests
        test_();
    </script>

/**
  * @param {String} url - address for the HTML to fetch
  * @return {String} the resulting HTML string fragment
  */
async function fetchHtmlAsText(url) {
    return await (await fetch(url)).text();
}

// this is your `load_home() function`
async loadHome() {
    const contentDiv = document.getElementById("content");
    contentDiv.innerHTML = await fetchHtmlAsText("home.html");
}

async function fetchHtmlAsText(url) {
    const response = await fetch(url);
    return await response.text();
}

$("#content").load("content.html");

$("#topBar").on("click",function(){
        $("#content").load("content.html");
});

async function load_home(){
  content.innerHTML = await (await fetch('home.html')).text();
}

async function load_home() {
  let url = 'https://kamil-kielczewski.github.io/fractals/mandelbulb.html'

  content.innerHTML = await (await fetch(url)).text();
}

<div id="topBar"> <a href="#" onclick="load_home()"> HOME </a> </div>
<div id="content"> </div>

$("button").click(function() {
    $("#target_div").load("requesting_page_url.html");
});

document.getElementById("target_div").innerHTML='';

function xml_add(pos, e, xml)
{
 e = (typeof e == 'string' && id_(e)) ? id_(e) : e;

 if (e.nodeName)
 {
  if (pos=='after') {e.parentNode.insertBefore(document.importNode(new DOMParser().parseFromString(xml,'application/xml').childNodes[0],true),e.nextSibling);}
  else if (pos=='before') {e.parentNode.insertBefore(document.importNode(new DOMParser().parseFromString(xml,'application/xml').childNodes[0],true),e);}
  else if (pos=='inside') {e.appendChild(document.importNode(new DOMParser().parseFromString(xml,'application/xml').childNodes[0],true));}
  else if (pos=='replace') {e.parentNode.replaceChild(document.importNode(new DOMParser().parseFromString(xml,'application/xml').childNodes[0],true),e);}
  //Add fragment and have it returned.
 }
}

element.appendChild(new DOMParser().parseFromString('<div xmlns="http://www.w3.org/1999/xhtml">'+id_('post_body').value+'</div>'),'application/xml'.childNodes[0]);

xml_add('after', id_(push_current_id()).tag_('footer')[0], '<div class="hidden" id="editor_rich_temp"></div>');

xml_add('before', $('#'+push_current_id()+' section')[0], '<h2 xmlns="http://www.w3.org/1999/xhtml"><span>Compose Message</span></h2>');

xml_add('inside', $('body > header > nav')[1], xml);

function $(o) {var r = false; if (document.querySelectorAll) {r = document.querySelectorAll(o);} return r;}

function class_(c) {return (document.getElementsByClassName(c)) ? document.getElementsByClassName(c) : false;}

function tag_(t) {return (document.getElementsByTagName(t)) ? document.getElementsByTagName(t) : false;}

Object.prototype.$ = function(c) {return (this.querySelectorAll && this.querySelectorAll(c) && this.querySelectorAll(c).length > 0) ? this.querySelectorAll(c) : false;}

Object.prototype.class_ = function(c) {return (this.getElementsByClassName && this.getElementsByClassName(c) && this.getElementsByClassName(c).length > 0) ? this.getElementsByClassName(c) : false;}

Object.prototype.tag_ = function(t) {return (this.getElementsByTagName && this.getElementsByTagName(t) && this.getElementsByTagName(t).length > 0) ? this.getElementsByTagName(t) : false;}

      <script type="text/javascript">
        function showHide(switchTextDiv, showHideDiv)
        {
          var std = document.getElementById(switchTextDiv);
          var shd = document.getElementById(showHideDiv);
          if (shd.style.display == "block")
          {
            shd.style.display = "none";
            std.innerHTML = "<span style=\"display: block; background-color: yellow\">Show</span>"; 
          }
          else
          {
            if (shd.innerHTML.length