Updating cakephp form input with javascript

Question

I'm having a lot of difficulty in updating a cakephp input, based on other inputs within the same cakephp form. Here is the code to form:

echo $this->Form->input('UnitPrice',['id'=>'unitPrice', 'type' => 'number']);    
echo $this->Form->input('SalePercent', ['id'=>'salePercent', 'type'=>'number']);
echo $this->Form->input('SalePrice', ['id'=>'salePrice', 'readonly'=>'readonly']);

Here is the jscript:

$('#salePercent').on('input', function() {
         calculate();
        });
        function calculate(){

            var sPercent = parseInt($('#salePercent').val());
            var sPrice="";
            if(isNaN(uPrice) || isNaN(sPercent)){
                sPrice=" ";
               }else{
               sPrice = (uPrice*(1-(sPercent/100))).toFixed(2);
               }

            $('#salePrice').val(sPrice);
        }

What im looking to achieve is have "SalePrice" update based on the "UnitPrice" and "SalePrice" entered. With my current code above, this is not happening. I get no response from the cakephp form field "SalePrice". Is this even possible?

Here is a jsfiddle of how i would like it to work

Im really sorry if this is a novice question, I am new to javascript.

Kind regards

Answer 1

Congratulations, it's already working! I tested the jsfiddle, and everything works.