Tstring error. What’s the problem ?

I can't get it, it was working fine and now I get this error ??????

PHP:

                              <?php

if (has_tag()) {

$tags = get_the_tags();

$html = ‘<div class="post_tags" onclick="javascript:_gaq.push([‘_trackSocial’, ‘Tags’, ‘Related’]);"><div id="tags">Tagged : </div>’;

foreach ( $tags as $tag ) {

    $tag_link = get_tag_link( $tag->term_id );      

    $html .= "<div  id="tags"><a href=’{$tag_link}‘ title=’{$tag->name}‘ >";

    $html .= "{$tag->name}</a></div>";

}

echo $html;

}…

Tstring error. What's the problem ?

See original post by bondigor69