Append link to head javascript

What I am trying to accomplish is use javascript to write a element in the section. The link element that i'm trying to add looks like this

As requested I've posted the entire code.:

    Extra-Life Alerts
    
    

    
        var effect = $.url[].param['effect'];
        var font = $.url[].param['font'];
        /*
         //document.getElementById["body"].innerHTML = document.write[''];
         //document.getElementById['head'].innerHTML += '';
         //var stylesheetAdd = '';

         $[function[] {
         $['head'].append[''];
         }];

         //var headID = document.getElementsByTagName["head"][0];
         //$[headID].append[''];
         //document.getElementById['#posts'].className = 'font-effect-' + effect;
         //document.getElementById['#posts'].style.fontFamily = font;
         //$["#posts"].className["font-effect-" + effect].style.fontFamily[font]; //= 'font-effect-' + effect;
         //$["#posts"].style.fontFamily[font]; //= font;
         //if [font] { $['.wf-active body, .wf-inactive body, #posts, body'].css['font-family', font]; }
         //else{font="Impact"; $['.wf-active body, .wf-inactive body, #posts, body'].css['font-family', font];}
         */
        /*
        //$['head'].append[''];
        var stylesheetAdd = '';
        //$['head'].append[''];
        $[stylesheetAdd].appendTo[document.head];
        */

        var headID = document.getElementsByTagName['head'][0];
        var link = document.createElement['link'];
        link.type = 'text/css';
        link.rel = 'stylesheet';
        link.href = '//fonts.googleapis.com/css?family=Oswald&effect=neon';
        headID.appendChild[link];

        /*
        var link = $['']
            .appendTo[document.getElementsByTagName['head'][0]]
            .attr['rel', "stylesheet"]
            .attr['type', "text/css"]
            .attr['href', "//fonts.googleapis.com/css?family=Oswald&effect=neon"];
        $[function[]{
           $[link];
        }];
        */
    

    








    var checkPriorDonorName = "prior name";
    var getCurrentDonorName = "current name";
    var checkPriorMessage = "prior message";
    var getCurrentMessage = "current message";

    function init[] {

        // Parse setup parameters.
        var id = $.url[].param['id'];
        var audio = $.url[].param['audio'];
        var playAudio = document.createElement["AUDIO"];

        var xmlhttp = new XMLHttpRequest[];
        //var url = "//2dc8c656ef.test-url.ws/tempDonations.txt";
        var url = "//www.extra-life.org/index.cfm?fuseaction=donorDrive.participantDonations&participantID=" + id + "&format=json";
        xmlhttp.open["GET", url, true];
        xmlhttp.send[];

        xmlhttp.onreadystatechange = function [] {
            getCurrentDonorName = xmlhttp.responseText;
            getCurrentMessage = xmlhttp.responseText
        };
        getCurrentDonorName = JSON.parse[getCurrentDonorName];
        getCurrentMessage = JSON.parse[getCurrentMessage];

        xmlhttp.onreadystatechange = function [] {
            if [[xmlhttp.readyState == '4' && [ xmlhttp.status == '200' || xmlhttp.status == '204' ]] &&
                    [ checkPriorDonorName === "prior name" || getCurrentDonorName[0].donorName != checkPriorDonorName ] &&
                    [ checkPriorMessage === "prior message"] || getCurrentMessage[0].message != checkPriorMessage] {
                extraLifeAlert[xmlhttp.responseText];
            }
            else
                return;
        };

        /** Debugging steps
         console.log["TEST BEGINNING NAME:   Current: " + getCurrentDonorName[0].donorName + " | Prior: " + checkPriorDonorName];
         console.log["TEST BEGINNING MESSAGE:   Current: " + getCurrentMessage[0].message + " | Prior: " + checkPriorMessage];
         */

        function extraLifeAlert[response] {
            var donorName = JSON.parse[response];
            var message = JSON.parse[response];
            var donationAmount = JSON.parse[response];

            if [donorName[0].donorName] {
                $['#posts'].find['.donorName'].text[donorName[0].donorName];
            }
            if [donationAmount[0].donationAmount] {
                $['#posts'].find['.donationAmount'].text[donationAmount[0].donationAmount];
            }
            if [message[0].message !== null] {
                $['#posts'].find['.message'].text[message[0].message];
            }
            else {
                $["#posts"].find[".message"].text[""];
            }

            //setTimeout[function[]{document.getElementById['#posts'].attr['style', 'display: none']}, 0];
            //setTimeout[function[]{document.getElementById['#posts'].attr['style', 'display: inline']}, 2000];
            setTimeout[function [] {
                document.getElementById['#posts'].style.display = 'none'
            }, 0];
            setTimeout[function [] {
                document.getElementById['#posts'].style.display = 'inline'
            }, 2000];
            if [audio] {
                playAudio.setAttribute["src", audio];
                playAudio.load[];
                playAudio.play[];
            }
            setTimeout[function [] {
                $["#posts"].fadeIn[1000];
            }, 1000];
            setTimeout[function [] {
                $["#posts"].fadeOut[1000];
            }, 10000];

            checkPriorDonorName = donorName[0].donorName;
            checkPriorMessage = message[0].message;
        }
    }
    /** Debugging steps
     console.log["TEST END NAME:   Current: " + getCurrentDonorName[0].donorName + " | Prior: " + checkPriorDonorName];
     console.log["TEST END MESSAGE:   Current: " + getCurrentMessage[0].message + " | Prior: " + checkPriorMessage];
     */
    setInterval[init, 5000];



    
 Just donated $.00 - 

Opps think i cut and pasted out some stuff. So the only think that matters to get this google font+effects to work is that 1]you add the tag in the , 2]add the font & effect class in the section where your text is. For right now i'm manually entered it in for testing purposes. I plan to control all this via script so that the user can put the options in the url and have it work.

How do you append a link in JavaScript?