Web Forms :: Counting Fields As Integers

I have 4 drop down menus labeled as with static input as

0-9; JobPerReview1 JobPerReview2 JobPerReview3 JobPerReview4

If for choice the user selects the following;

JobPerReview1 = 3JobPerReview2 = 0JobPerReview3 = 5JobPerReview4 = 9

I would like a function/ script to sum the total inputs as an integer or if that's the correct term for it. So it would calculate something like thisJob

PerReview1 = 3 summed as 1JobPerReview2 = 0 summed as noneJobPerReview3 = 5 summed as 1JobPerReview4 = 9 summed as 1

I would also like a total box labeled "NOF (number of factors)to calculate the selections such as;

NOF = 3

This is starting to be mind bugling function

getItems(){var items = new Array();var itemCount = document.getElementsByClassName("items");
var total = 0;var id= '';for(var i = 0; i < itemCount.length; i++){id = "p"+(i+1);total = total + parseInt(document.getElementById(id).value);
} document.getElementById('tot').value = total;return total;
} getItems();
function getItems() {
var items = new Array();

[Code]....