title: calculate form fields using jquery
body: <p>i want a jquery source to calculate my form</p>
  
  <pre><code>&lt;form&gt;
        &lt;input type="radio" name="type" value="1000"&gt; $1000
        &lt;input type="radio" name="type" value="2000"&gt; $2000
        &lt;input type="radio" name="type" value="3000"&gt; $3000
        &lt;input type="radio" name="type" value="4000"&gt; $4000
        &lt;input type="radio" name="type" value="5000"&gt; $5000
  
      &lt;select name="number"&gt;
        &lt;option name="number" value="1"&gt;1&lt;/option&gt;
        &lt;option name="number" value="1"&gt;2&lt;/option&gt;
        &lt;option name="number" value="1"&gt;3&lt;/option&gt;
        &lt;option name="number" value="1"&gt;4&lt;/option&gt;
        &lt;option name="number" value="1"&gt;5&lt;/option&gt;
      &lt;/select&gt;
  
  &lt;/form&gt;
  </code></pre>
  
  <p>must type*number and show total in text input</p>