Javascript checkbox sum

I have this assignment that I'm supposed to make an "Order" page with a form and items in the checkbox format. I wrote a function in javascript to add the values of the marked checkboxes together and return me a total. It was working fine yesterday, but I might have done something yesterday without noticing and it is not adding the values anymore.

Here is the function:

function totalIt() {
  var input = document.getElementsByName("product");
  var total = 0;
  for (var i = 0; i < input.length; i++) {
    if (input[i].checked) {
      total += parseFloat(input[i].value);
    }
  }
  document.getElementByName("total").value = "$" + total.toFixed(2);
}

Select your items:
<br>
<input name="product" value="3.65" type="checkbox" onclick="totalIt()" /> Item 1 - $3.65
<br>
<input name="product" value="5.50" type="checkbox" onclick="totalIt()" /> Item 2 - $5.50
<br>
<input name="product" value="3.29" type="checkbox" onclick="totalIt()" /> Item 3 - $3.29
<br>
<input name="product" value="7.99" type="checkbox" onclick="totalIt()" /> Item 4 - $7.99<br>
<input name="product" value="5.45" type="checkbox" onclick="totalIt()" /> Item 5 - $5.45<br>
<input name="product" value="99.99" type="checkbox" onclick="totalIt()" /> Item 6 - $99.99<br>
<input name="product" value="30.00" type="checkbox" onclick="totalIt()" /> Item 7 - $30.00
<br> Total:
<br>
<input value="$0.00" readonly="readonly" type="text" name="total" />

Am I not seeing something?