title: javascript to calculate simple multiplication automatically upon changing any number
body: <p>I'm not a javascript programmer, but I have to use it for a calculation I need to do on a wordpress page. </p>
  
  <p>Here is what I need:</p>
  
  <ul>
  <li>3 fields in html where I can enter a number (a form). </li>
  <li>a text field where the multiplication is "printed" </li>
  <li>if I change one element, a new result must apear, without me needing to push any button. </li>
  </ul>
  
  <p>any idea on how to do this? 
  I know how to do the calculation as such, but not that it works automatically. </p>
  
  <p>HEre is what I got so far:</p>
  
  <pre><code>    &lt;html&gt;
  
  &lt;head&gt;
  
  &lt;title&gt;Simple Javascript Calculator - Basic Arithmetic Operations&lt;/title&gt;
  
  
  &lt;script language="javascript" type="text/javascript"&gt;
  function multiply(){
      a=Number(document.calculator.number1.value);
      b=Number(document.calculator.number2.value);
      c=a*b;
      document.calculator.total.value=c;
  }
  &lt;/script&gt;
  
  
  
  &lt;/head&gt;
  
  &lt;body&gt;
  
  &lt;!-- Opening a HTML Form. --&gt; 
  &lt;form name="calculator"&gt;
  
  &lt;!-- Here user will enter 1st number. --&gt; 
  Number 1: &lt;input type="text" name="number1"&gt; 
  
  
  &lt;!-- Here user will enter 2nd number. --&gt; 
  Number 2: &lt;input type="text" name="number2"&gt; 
  
  
  &lt;!-- Here result will be displayed. --&gt; 
  Get Result: &lt;input type="text" name="total"&gt; 
  
  
  &lt;!-- Here respective button when clicked, calls only respective artimetic function. --&gt; 
  &lt;&lt;input type="button" value="MUL" onclick="javascript:multiply();"&gt;
  
  
  &lt;/form&gt;
  
  &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>
  
  <p>thanks</p>