selectbox value calculation
<p>I want to do a calculation between selectbox values. The problem with my code is that the first part of the calculation only gives me <code>0</code>, which Motherboard value*quantity. the second part works fine which Chassis*quantity. My formulas is <code>motherbord*Quanity+chassis*quantity</code>. </p>

<p>Here is my code: </p>

<pre><code>function calculate() {
    var parsedMotherboard = parseFloat(document.calcform.Motherboard.value || 0);
    var parsedQuantity = parseFloat(document.calcform.Quantity.value || 0);
    var parsedChassis = parseFloat(document.calcform.Chassis.value || 0);
    var parsedQuantity1 = parseFloat(document.calcform.Quantity1.value || 0);

    document.calcform.total.value = (parsedMotherboard * parsedQuantity + parsedChassis * parsedQuantity1);
}
</code></pre>

<p><img src="http://i.stack.imgur.com/LnHKt.jpg" alt="interface"></p>
