Question

I have this code:

<script type="text/javascript">
function showTotal(form, totalEl)
{
  var el, els = form.elements;
  var sum = 0;

  for (var i=0, num=els.length; i<num; ++i){
    el = els[i];

    if ('text' == el.type){ //&& /SumB/.test(el.name)
      sum += +el.value;
    }
    form.elements[totalEl].value = sum;
  }
}
</script>

If I use an alert I get the correct output but it fills the wrong value into “totalEl” You can test this on (fixed) It’s the first block of checkboxes and textboxes!

Answer 1

Does it work if you try

<script type="text/javascript">
function showTotal(form, totalEl)
{
  var el, els = form.elements;
  var sum = 0;

  for (var i=0, num=els.length; i<num; ++i){
    el = els[i];

    // Do not include totalEl
    if ('text' == el.type && el != form.elements[totalEl]) {
      sum += +el.value;
    }
  }
  form.elements[totalEl].value = sum;
}
</script>

If totalEl is an element of the form, then the form.elements[totalEl].value = sum; line must be outside the for loop, otherwise the value of totalEl itself will be included in the last calculation, resulting in a double sum.