Highilight line in textarea

Пример подсветки текущей строки в textarea
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
  <head>
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
    <title>Untitled Document</title>
    <script type="text/javascript" src="http://code.jquery.com/jquery-1.4.2.min.js"></script>
    <!-- http://code.google.com/p/jcaret/ -->
    <!--<script type="text/javascript" src="/images/wp/jquery.caret.1.02.min.js"></script>-->
    <script type="text/javascript">
      $(function () {
        $('#data').keyup(highlightTextArea).mouseup(highlightTextArea).scroll(highlightTextArea)
      })

      function highlightTextArea() {
        var m = $.browser.msie || $.browser.opera ? 2 : 1
        var count = $('#data').caret().start
        var lines = $('#data').val().split('\n')
        for (var i = 0; i < lines.length; i++) {
          count = count - lines[i].length - m
          if (count < 0) break
        }

        var lineHeight = parseInt($('#data').css('line-height'))
        if (isNaN(lineHeight)) lineHeight = 16
        var top = i * lineHeight - $('#data').scrollTop()
        top = '0 ' + parseInt(top) + 'px'
        $('#data').css('background-position', top)
      }
    </script>
    <style type="text/css">
      #data {
        padding: 0;
        border: 1px solid #999;
        font: 14px/16px Arial;
        background: #fff url(z.png) repeat-x 0 0;
      }
    </style>
  </head>

  <body>
    <textarea name="data" id="data" rows="10" columns="50" wrap="off">
1. line
2. line
3. line
4. line
5. line
6. line
7. line
8. line
9. line
10. line
11. line
12. line
13. line
14. line
15. line</textarea
    >
  </body>
</html>