google java script in sitemap

I got this java script, that I inserted in my pages in order to have them indexed by google, at the beginning of my sitemap_index.hml:

<script type="text/javascript">

  var _gaq = _gaq || [];
  _gaq.push(['_setAccount', 'UZ-123456789-1']);
  _gaq.push(['_trackPageview']);

  (function() {
    var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;
    ga.src = ('https:' == document.location.protocol ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';
    var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);
  })();

</script>

This results in having an error message:

error on line 14 at column 6: XML declaration allowed only at the start of the document

What is worst, Google analytic doesn’t recognize the file.
I eliminated the script from each page and article, but it is still present in the sitemape_index and I am not able to change that.
How can I regenerate the sitemap? Help please.
My site is velespiegate.it.

http://ww.wp.xz.cn/extend/plugins/wordpress-seo/