title: dont know what script will i put
body: <p>i want to have this result
  <code>http://farm8.staticflickr.com/7291/11250276724_fc1f751dc0_o.png</code></p>
  
  <p>this is the pic that i want to become result</p>
  
  <p>but i dont know the script can someone help me </p>
  
  <pre><code>&lt;!DOCTYPE html&gt;
  &lt;html&gt;
    &lt;head&gt;
      &lt;script&gt;
        function myFunction()
      &lt;/script&gt;
    &lt;/head&gt;
  
    &lt;body&gt;
      &lt;form&gt;
        &lt;input type="checkbox" id="bike"&gt;100&lt;br&gt;
        &lt;input type="checkbox" id="bike2"&gt;100&lt;br&gt;
        &lt;input type="checkbox" id="bike3"&gt;100&lt;br&gt;
        &lt;button type="button" onclick="myFunction()"&gt;Equal&lt;/button&gt;
        &lt;input type="text" id="total"&gt;
      &lt;/form&gt;
    &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>
  
  <p>i just want an output that example when i check one checkbox and click the equal the total will be 100 but when i check two checkbox and i click the equal the total will be 200. and the total will display in text. </p>