WTH Javascript/ HTML/CSS coder to fix one page function

Im looking to hire a coder that can fix a Javascript issue for me, im working on a site where im stuck at a function. What im trying to do is a function like this page here http://www.mardmedia.se/webbpaket/ where you click on the options on the lower half of the page you get the sum of the cost for that function added to the total cost. I have the script seen here http://www.javascriptbank.com/simple-javascript-auto-sum-with-checkboxes.html

What im stuck at is that the javascript wont work in my <ul><li> TAGS


So i need you to fix this issue in a cross-browser friendly way and tune the script to fit my page looks.



PM me your timetable and a quote, do NOT pm me asking for a budget.

 

ok I got some PMs but still nothing im happy with..


ill pay $5 for you to show me a way to get this to work, it must be cross browser compatible tho...


Here is the JS code

<script type="text/javascript">
// Created by: Jay Rumsey | [url]http://www.nova.edu/~rumsey/[/url]
// This script downloaded from JavaScriptBank.com

function UpdateCost() {
  var sum = 0;
  var gn, elem;
  for (i=0; i<5; i++) {
    gn = 'game'+i;
    elem = document.getElementById(gn);
    if (elem.checked == true) { sum += Number(elem.value); }
  }
  document.getElementById('totalcost').value = sum.toFixed(2);
} 
</script>

Code (markup):

Here is the HTML code for the JS function

<input type="checkbox" id='game0' value="9.99"  onclick="UpdateCost()">Game 1 ( 9.99)<br>
<input type="checkbox" id='game1' value="19.99" onclick="UpdateCost()">Game 2 (19.99)<br>
<input type="checkbox" id='game2' value="27.50" onclick="UpdateCost()">Game 3 (27.50)<br>
<input type="checkbox" id='game3' value="45.65" onclick="UpdateCost()">Game 4 (45.65)<br>

HTML:

Here is my HTML code where i want the checkboxes in

<ul class="BorderStyleLt">
              <li></li>
              <li></li>
              <li></li>
              <li></li>
            </ul>

HTML:

The only "problem" is the output (the sum) must be styles as the rest of the page is, which is

.Style03{
	font-size:24px !important;
	font-weight:bold;
	color:#00cece !important;
	}

Code (markup):