Hi, Here is your solution.
I analysed your code and i found a bug in your code. you just create a mistake in your "totalDue" function. and here the function code
function totaldue()
{
var total=parseInt(document.getElementById('total').innerHTML);
var paid=parseInt(document.getElementById('paid').value);
if(isNaN(paid))
paid=0;
var totaldue=parseInt(document.getElementById('totaldue').innerHTML);
var totaldue1=Math.abs((total-paid).toFixed(2));
document.getElementById("totaldue").innerHTML=totaldue1;
}
And another thing i found in your code, there is no "result" function but you used in following line, which you've to remove.
<input type="text" id="subtotal" name="subtotal" onKeyUp="result(this.form)" onKeyUp="taxcal(this.form)" class="subtotal" value="0.00" style="border:none;width: 100%;"/>
and that line should be like following
<pre><input type="text" id="subtotal" name="subtotal" onKeyUp="taxcal(this.form)" class="subtotal" value="0.00" style="border:none;width: 100%;"/>