Submit a form by selecting a dropdown item in JavaScript

How's this done? Check the Source Code:

<form action="./" method="GET">
 <div align="center"">
  <select name="state" onchange="this.form.submit();">
    <option>Choose One To Submit This Form</option>
    <option value="CA">CA</option>
    <option value="VA">VA</option>
  </select>
 </div>
</form>