prevent form submission using jquery

JavaScript
    //option A
    $("form").submit(function(e){
        e.preventDefault();
    });<html>
    <head>
        <script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.7.1/jquery.min.js"></script>
        <script type='text/javascript'>
         $(document).ready(function() {
            //option A
            $("form").submit(function(e){
                alert('submit intercepted');
                e.preventDefault(e);
            });
        });
        </script>
    </head>

    <body>
        <form action="page_url" method="GET">
          Search <input type='text' name='q' />
          <input type='submit'/>
        </form>
    </body>
</html>
Source