Changing Calculation In Simple Interest Calculator

The exercise problem is to "MODIFY the code in the "calculate_click" event so interest is added to future value just once each year for the number of years that they were entered by the user". The calculation as you see it below assumes an amount is invested MONTHLY (not just once), and the interest is calculated accordingly. This is what I think the problem is trying to calculate: using a $100 one time investment at 10% interest (compounded once annually) for one year = $110 as the future value. For two years, the future value should equal $121 (110 + (110*.10)). Okay, if my math is wrong, let me know. This is what I'm trying to get it to match to.

I have been able to modify the calculate_click function to compound the interest annually (it does it monthly now). Cool. I cannot get it to stop adding $100 annually. See my math above? I think that's the answer. My manipulation of the code yields $110 for the first year, $231 for the second year, etc. The $231 is incorrect cuz it adds an extra $100. See, this is a simple interest calculator I can't figure out! The original code is below that calculates the investment as a monthly investment as opposed to one-time. To avoid confusion, I did not include any of my modifications. But yeah. I know that the major culprit is how the "for" loop is being executed. I've highlighted where I think the code needs to be changed, but I haven't changed it here. Note the first function is a shortcut to execute getElementbyID.

The Code:
var $ = function (id) {
return document.getElementById(id);
} var calculate_click = function () {
var investment = parseFloat( $("investment").value );
var annualRate = parseFloat( $("rate").value );
var years = parseInt( $("years").value );
$("futureValue").value = ""; .....