This JavaScript code example uses a for loop to calculate the sum of JavaScript checkbox values. This JavaScript will display a running total automatically wh... detail at JavaScriptBank.com - 2.000+ free JavaScript codes


How to setup

Step 1: Copy & Paste JavaScript code below in your HEAD section
JavaScript
Code:
<script type="text/javascript">
// Created by: Jay Rumsey | http://www.nova.edu/~rumsey/
// 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>
Step 2: Copy & Paste HTML code below in your BODY section
HTML
Code:
<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>
<input type="checkbox" id='game4' value="87.20" onclick="UpdateCost()">Game 5 (87.20)<br>