Random posts by label

Hello guys,

i want to ask for your help once again.
Bellow is a working code for random post sidebar widget. Its working great … but i want a bit more.
I want to ask if you can help me out to made this script for a certain label; to show only posts with a certain label, not random posts from across my blog.

Thank you.

<ul id='random-posts'>
    <script type='text/javaScript'>
        var tow_numposts=5;
		var tow_snippet_length=150;
		var tow_info='yes';
		var tow_comment='Comments';
		var tow_disable='Comments Disabled';
		var tow_current=[];
		var tow_total_posts=0;
		var tow_current=new Array(tow_numposts);function totalposts(json){tow_total_posts=json.feed.openSearch$totalResults.$t}document.write('
        <script type=\\ "text/javascript\\" src=\\ "/feeds/posts/default?alt=json-in-script&max-results=0&callback=totalposts\\">
            < \\/script>');function getvalue(){for(var i=0;i<tow_numposts;i++){var found=false;var rndValue=get_random();for(var j=0;j<tow_current.length;j++){if(tow_current[j]==rndValue){found=true;break}};if(found){i--}else{tow_current[i]=rndValue}}};function get_random(){var ranNum=1+Math.round(Math.random()*(tow_total_posts-1));return ranNum};
        </script>
        <script type='text/javaScript'>
            function random_posts(json){for(var i=0;i
            <tow_numposts;i++){var entry=json.feed.entry[i];var tow_posttitle=entry.title.$t;if( 'content'in entry){var tow_get_snippet=entry.content.$t}else{if( 'summary'in entry){var tow_get_snippet=entry.summary.$t}else{var tow_get_snippet="" ;}};tow_get_snippet=tow_get_snippet.replace(/<[^>]*>/g,"");if(tow_get_snippet.length
                <tow_snippet_length){var tow_snippet=tow_get_snippet}else{tow_get_snippet=tow_get_snippet.substring(0,tow_snippet_length);var space=tow_get_snippet.lastIndexOf( " ");tow_snippet=tow_get_snippet.substring(0,space)+ "…";};for(var j=0;j<entry.link.length;j++){if( 'thr$total'in entry){var tow_commentsNum=entry.thr$total.$t+ ' '+tow_comment}else{tow_commentsNum=tow_disable};if(entry.link[j].rel=='alternate' ){var tow_posturl=entry.link[j].href;var tow_postdate=entry.published.$t;if( 'media$thumbnail'in entry){var tow_thumb=entry.media$thumbnail.url}else{tow_thumb="http://2.bp.blogspot.com/-XQt2v4x5dl8/T1zdpFh392I/AAAAAAAABUU/xMJZDedw38k/s1600/default.jpg" }}};document.write( '<li>');document.write( '<img alt="'+tow_posttitle+ '" src="'+tow_thumb+ '"/>');document.write( '<div><a href="'+tow_posturl+ '" rel="nofollow" title="'+tow_snippet+ '">'+tow_posttitle+ '</a></div>');if(tow_info=='yes' ){document.write( '<span>'+tow_postdate.substring(8,10)+ '/'+tow_postdate.substring(5,7)+ '/'+tow_postdate.substring(0,4)+ ' - '+tow_commentsNum)+ '</span>'}document.write( '<div style="clear:both"></div></li>')}};getvalue();for(var i=0;i<tow_numposts;i++){document.write( '<script type=\\"text/javascript\\" src=\\"/feeds/posts/default?alt=json-in-script&start-index='+tow_current[i]+ '&max-results=1&callback=random_posts\\"><\\/script>')}; </script>
                    <p><a href="http://www.talkofweb.com/show-random-posts-with-thumbnails-in-blogger" rel="nofollow" title="Talk of web Blogger Widgets">Grab this Widget</a>
                    </p>
</ul>
<style type='text/css'>
    #random-posts img {
        float: left;
        margin-right: 10px;
        border: 1px solid #999;
        background: #FFF;
        width: 100px;
        height: 100px;
        padding: 3px
    }
    #random-posts li {
        margin: 0px 0px 10px 0px;
    }
</style>