Need Help With Check Box count Script

Question

Need to count the number of checked boxes. I'm using the script below and its not working. What I'm I doing wrong? It's driving me crazy.
// document level function to sum named fields
function Sum(aFieldNames) {
var sum = 0; // sum of values
// loop through fields
for (var i = 0; i < aFieldNames.length; i++) {
if(!isNaN(this.getField(aFieldNames[i]).value) )
sum += Number(this.getField(aFieldNames[i]).value);
return sum;
} // end of Sum function
// array of field names sum
var aCheckBox = new Array('Check Box5', 'Check Box8', 'Check Box11', 'Check Box16', 'Check Box19','Check Box22', 'Check Box25','Check Box28', 'Check Box31', 'Check Box34','Check Box37', 'Check Box40','Check Box43', 'Check Box46', 'Check Box49','Check Box52', 'Check Box55','Check Box58', 'Check Box61', 'Check Box64','Check Box68');
// sum named fields
event.value = Sum(aCheckBox);

Answer 1

Then why are you checking if they're a number by using the isNaN function, and then trying to add that number to the sum variable? It looks like you just copied the code from somewhere else, even though it doesn't apply to your situation.
Replace those two lines of the code with this:
if (this.getField(aFieldNames[i]).value!="Off") sum++;