/* This script and many more are available free online at
The JavaScript Source :: http://javascript.internet.com
Created by: Jay Rumsey :: http://www.nova.edu/~rumsey/
Modified 22/10/09: 4th line = total number of discs + 2 postage items  
*/

 function UpdateCost() {
  var sum = 0;
  var gn, elem;
  for (i=0; i<26; i++) {
    gn = 'item'+i;
    elem = document.getElementById(gn);
    if (elem.checked == true) { sum += Number(elem.value); }
  }
  document.getElementById('totalcost2009').value = sum.toFixed(2);
  document.getElementById('totalcost2008').value = sum.toFixed(2);
}