var out = document.getElementById("output2");
var args = ["About", "Games", "The Hideout", "Staff", "Contact Us",];

function displayMenu() {
    var ul = document.createElement('ul');
    ul.className = "mainMenu";
    args.forEach(function(name, index) {
        var li = document.createElement('li'),
            an = document.createElement('a');
        li.className = "mmenu-item-" + index;
        li.setAttribute = "link rel", "stylesheet", "type", "text/css", "href", "http://www.thegaminghideout.com/style.css";
        an.innerHTML = name;
        an.setAttribute('href', "http://www.thegaminghideout.com/" + name + ".html");
        li.appendChild(an);
        ul.appendChild(li);
    });
    out.appendChild(ul);
}

<div id="navigation">
    <div class="navlinks">
        <div id="output2">
            <ul class="mainMenu">
                <li class="mmenu-item-0">
                    <a href="http://www.thegaminghideout.com/About.html">About</a>
                </li>
                <li class="mmenu-item-1">
                    <a href="http://www.thegaminghideout.com/Games.html">Games</a>
                </li>
                <li class="mmenu-item-2">
                    <a href="http://www.thegaminghideout.com/The Hideout.html">The Hideout</a>
                </li>
                <li class="mmenu-item-3">
                    <a href="http://www.thegaminghideout.com/Staff.html">Staff</a>
                </li>
                <li class="mmenu-item-4">
                    <a href="http://www.thegaminghideout.com/Contact Us.html">Contact Us</a>
                </li>
            </ul>
        </div>
    </div>
    <script src="http://www.thegaminghideout.com/nav.js"></script>
</div>

var out = document.getElementById("output2");
var x = document.getElementByTagName("LI");
var args = ["URL1", "URL2", "URL3", "URL4", "URL5",];
function displayMenu() {
    var ul = document.createElement('ul');
    ul.className = "mainMenu";
    args.forEach(function(name, index) {
        var li = document.createElement('li'),
            an = document.createElement('a');
        li.className = "mmenu-item-" + index;
        li.setAttribute = "link rel", "stylesheet", "type", "text/css", "href", "http://www.thegaminghideout.com/style.css";
        an.innerHTML = name;
        an.setAttribute('href', "http://www.thegaminghideout.com/" + name + ".html");
        li.appendChild(an);
        ul.appendChild(li);
    });
    out.appendChild(ul);

#navigation  {
    width: 760px;
    height: 35px;
    position: absolute;
    border-bottom: 2px solid #000000;
    background: orange;
    padding: 0px;
}
#navigation .padding  {
    padding: 2px;
}
#navigation .navlinks  {
    position: absolute;
    top: 1px; left: 0px;
}
#navigation .navlinks ul  {
    margin: 0px;
    padding: 0px;
    text-align: center;
    list-style-type: none;
    width: 760px;
    height: 35px;
}
#navigation .navlinks li {
    position: relative;
    top: 5px;
    margin: 0px 5px 0px 5px;
    list-style-type: none;
    display: inline;
}
#navigation .navlinks li a  {
    color: #000000;
    padding: 5px 0px 9px 0px;
    text-decoration: none;
    font-size: 18px;
    font-family: karmatic_arcaderegular;
    padding: 5px 0px 9px 0px;
}
#navigation .navlinks li a:hover  {
    margin: 0px;
    color: #ffffff;
    background: orange;
    text-decoration: underline;
}