如何在每次创建注释时自动化在wordpress中添加注释链接的过程

so we are making a wordpress site that automatically adds a link to a comment every time a comment is created. The theme we are using is html5 blank. I have written several lines of code into its function.php. however it is not working right now, here is what i wrote:

function bo_wrap_comment_text($content) {
    $content = get_comment_text();
    $texta = urlencode(get_comment_text());
    $textb = "http://www.google.com/search?btnI&q=" + $texta;
    return '<a href="'.$textb.'">'.$content.'</a>';
}
add_filter('wp_insert_comment','bo_wrap_comment_text',1000);

a separate code(this one works) is tested here: http://phpfiddle.org and the code is:

   <?php 
        $texta='i hate apple';
        $textb=urlencode($texta);
        $textc= "http://www.google.com/search?btnI&q=".$textb;
        echo '<a href="'.$textc.'">'.$texta.'</a>';
   ?>

the wordpress site is here. It is simply a static front page. the title you see there is the title of comment area. everything related with blog posts has been hidden using css. we have manually added links to several comments as prototyping. what we want is replace manual work with wordpress functions. I would really appreciate any help.