Advanced handling of Wufoo url query params

gistfile1.js

<div id="wufoo-m2oq9xw0yusu89"></div>
<script type="text/javascript">
    var QueryString = function () {
      /*
      This function is anonymous, is executed immediately and
      the return value is assigned to the variable 'QueryString'
      */
      var query_string = {};
      var query = window.location.search.substring(1);
      var vars = query.split("&");
      for (var i=0;i<vars.length;i++) {
        var pair = vars[i].split("=");
          // If first entry with this name
        if (typeof query_string[pair[0]] === "undefined") {
          query_string[pair[0]] = pair[1];
          // If second entry with this name
        } else if (typeof query_string[pair[0]] === "string") {
          var arr = [ query_string[pair[0]], pair[1] ];
          query_string[pair[0]] = arr;
          // If third or later entry with this name
        } else {
          query_string[pair[0]].push(pair[1]);
        }
      }
        return query_string;
    } ();
    // Let's get the defaultValues properly!
    var defaultValues = function() {
      var defaultArray = [];
      var defaultValues = "";
      // Define the URL paramters you would like to capture
      // eg. {'field1' : QueryString.name} or {'field99' : QueryString.email}
      var urlParams = [
      {'field1' : QueryString.cool},
      {'field2' : QueryString.awesome}
      ];
      // Let's loop thorugh and find which params we have today
      for (var i = urlParams.length - 1; i >= 0; i--) {
        var value = urlParams[i];
        var check = value[Object.keys(value)[0]];
        if(typeof check !== 'undefined') {
          defaultArray.push(urlParams[i]);
        }
      };
      // Now we have those params, let's set the real 'defaultValues'
      for (var i = defaultArray.length - 1; i >= 0; i--) {
        var item = defaultArray[i];
        var key = Object.keys(item)[0];
        var prop = item[key];
        if (defaultValues === "") {
          //defaultValues = "'" + key + '=' + prop + "'";
          defaultValues = key + '=' + prop;
        } else {
          var str = defaultValues.concat("&" + key + '=' + prop);
          defaultValues = str;
        };
      };
      return defaultValues;
    };
      var defaultValues = defaultValues();
      console.log(defaultValues);
      var m2oq9xw0yusu89;(function(d, t) {
        var s = d.createElement(t), options = {
        'userName':'beingremarkable',
        'formHash':'m2oq9xw0yusu89',
        'autoResize':true,
        'height':'828',
        'async':true,
        'host':'wufoo.com',
        'header':'hide',
        'ssl':true,
        'defaultValues': defaultValues};
        s.src = ('https:' == d.location.protocol ? 'https://' : 'http://') + 'wufoo.com/scripts/embed/form.js';
        s.onload = s.onreadystatechange = function() {
        var rs = this.readyState; if (rs) if (rs != 'complete') if (rs != 'loaded') return;
        try { m2oq9xw0yusu89 = new WufooForm();m2oq9xw0yusu89.initialize(options);m2oq9xw0yusu89.display(); } catch (e) {}};
        var scr = d.getElementsByTagName(t)[0], par = scr.parentNode; par.insertBefore(s, scr);
      })(document, 'script');
    </script>