Add word count to excerpts

/** Add word count to excerpts */
function excerpt_count_js() {
    if ('page' != get_post_type()) {
    ?>
    <style>.span-excerpt_counter{font-size:12px;font-weight:normal;float:right;}</style>
    <?php
        echo '<script>jQuery(document).ready(function($) {
        $("#postexcerpt .hndle").append("<span class=\"span-excerpt_counter\">Excerpt length: <span id=\"excerpt_counter\"></span><span> / 10 </span><span>character(s).</span></span>");
            $("span#excerpt_counter").text($("#excerpt").val().length);
            $("#excerpt").keyup( function() {
                if($(this).val().length >= 10) {
                $("span#excerpt_counter").css("color", "red");
                    $(this).val($(this).val().substr(0, 10));
                }else{
                $("span#excerpt_counter").css("color", "");
                }
            $("span#excerpt_counter").text($("#excerpt").val().length);
            });
        });</script>';
        }
    }
add_action( 'admin_head-post.php', 'excerpt_count_js');
add_action( 'admin_head-post-new.php', 'excerpt_count_js');