title: How to make the calculate button work
body: <p>I have this code that I'm working on, but the calculate button won't work no matter what I do. I want to find the cost per square inch using the pizzaSize and pizzaCost. How can I make the calculate button actually calculate?</p>
  
  <pre><code>&lt;!DOCTYPE html&gt;
  &lt;html lang='en'&gt;
  &lt;head&gt;
  &lt;meta charset='utf-8' &gt;
  &lt;title&gt; Pizza Calculator &lt;/title&gt;
  &lt;script src="pizzaCalc.js"&gt;
  &lt;/script&gt;
  &lt;/head&gt;
  &lt;body&gt;
  &lt;h1&gt;Pizza Calculator&lt;/h1&gt;
  &lt;p&gt;
  &lt;label for="priceBox"&gt;Cost: &lt;/label&gt;&lt;input type="text" id="priceBox" size="5"/&gt;&lt;/p&gt;
  &lt;p&gt;
      &lt;label for="sizeBox"&gt;Diameter :&lt;/label&gt;&lt;input type="text" id="sizeBox"     
      size="5"/&gt;
  &lt;/p&gt;
  &lt;input type="button" id="cpsi" value="Cost PSI" onclick="calculate(cpsi)"&gt;
  
  &lt;/body&gt;
  &lt;/html&gt;
  
  "use strict"
  function pizzaCalc () {
      var size = document.getElementById ("sizeBox").value;
      size = parseFloat (size);
      var price = document.getElementById("priceBox").value;
      price = parceFloat (price);
      var costPerSquareInch = price / (3.14 * (size / 2)^2)
      alert('Pizza value :' +costPerSquareInch);
      document.getElementById("cpsi").value = costPerSquareInch;
  }
  </code></pre>