magazine-columns.php edited for archives etc

<?php
/*
Plugin Name: Magazine Columns
Plugin URI: http://bavotasan.com/downloads/magazine-columns-wordpress-plugin/
Description: Divides your post or page content into two or more columns, like a magazine article.
Author: c.bavota
Version: 1.0.4
edited 21/11/2011 to work in multipost pages such as index and archives
Author URI: http://www.bavotasan.com/
*/

// Replace the_content function if a <!--column--> tag is detected
function add_columns($content) {
    if(stristr($content, '<!--column-->') ) {
    $return_value = ''; //the variable for the columnated content
        if(stristr($content, '<!--startcolumns-->')) {
            $topcontent = explode('<!--startcolumns-->', $content);
            if(stristr($content, '<!--stopcolumns-->')) {
                $bottomcontent = explode('<!--stopcolumns-->', $topcontent[1]);
                $content = preg_replace('/width="([0-9]*)" height="([0-9]*)"/', '',$bottomcontent[0]);
            } else {
                $content = preg_replace('/width="([0-9]*)" height="([0-9]*)"/', '',$topcontent[1]);
            }
        } else {
            $content = preg_replace('/width="([0-9]*)" height="([0-9]*)"/', '',$content);
        }
        $content = explode('<!--column-->', $content);
        $count = count($content);
        if($count == 2) {
            $colname = "col_two";
        } elseif($count == 3) {
            $colname = "col_three";
        } elseif($count == 4) {
            $colname = "col_four";
        } else {
            $colname = "col_five";
        }
        $x = 1;
        if(!empty($topcontent[0])) {
            $top = explode('<br />',$topcontent[0]);
            $i = count($top);
            $top[$i-1] .= '</p>'."\n";
            $top = implode("", $top);
            $return_value .= $top;
        }
        foreach($content as $column) {
            $output = "\n".'<div class="columns '.$colname.$x.'">'.$column.'</div>'; //edited to css classes
            $output = str_replace('<div class="columns '.$colname.$x.'"><br />','<div class="columns '.$colname.$x.'"><p>', $output);
            if($x == 5) {
                unset($content[0]);
                unset($content[1]);
                unset($content[2]);
                unset($content[3]);
                $column = implode("", $content);
                $return_value .= $output;
                break;
            } else {
            $return_value .= $output;
            }
            $x++;
        }
        if(!empty($bottomcontent[1])) {
            $bottom = explode('<br />',$bottomcontent[1]);
            $bottom[0] = '<p style="clear: both;">' . $bottom[0];
            $bottom = implode("", $bottom);
            $return_value .= $bottom;
        }
        return force_balance_tags($return_value); //repair some of the invalid codes
    } else {
        return $content;
    }
}

// Adds the add_columns() function to the_content()
add_filter('the_content', 'add_columns');

// Creates the CSS for columns
// edited to use css classes and to always output all possible classes
function add_columns_css() {
    global $post;
    $content = $post->post_content;
    if(stristr($content, '<!--column-->') ) {
        $content = explode('<!--column-->', $content);
        $count = count($content);

        $two = 47; // width of two columns
        $three = 29.5; // width of three columns
        $four = 21; // width of four columns
        $five = 15; // width of five columns
        echo '<!-- Magazine Columns CSS -->'."\n";
        echo "<style type='text/css'>\n";
        if($count >=1) {
        echo " .col_two1 { float: left; width: ".$two."%; }\n";
        echo " .col_two2 { float: left; width: ".$two."%; margin: 0 0 0 5%; }\n";
        }
        if($count >=1) {
        echo " .col_three1, #col_three3 { float: left; width: ".$three."%; }\n";
        echo " .col_three2 { float: left; width: ".$three."%; margin: 0 5%; }\n";
        }
        if($count >=1) {
        echo " .col_four1, #col_four4 { float: left; width: ".$four."%; }\n";
        echo " .col_four2 { float: left; width: ".$four."%; margin: 0 2.5% 0 5%; }\n";
        echo " .col_four3 { float: left; width: ".$four."%; margin: 0 5% 0 2.5%; }\n";
        }
        if($count >=1) {
        echo " .col_five1, #col_five5 { float: left; width: ".$five."%; }\n";
        echo " .col_five2 { float: left; width: ".$five."%; margin: 0 2.5% 0 5%; }\n";
        echo " .col_five3 { float: left; width: ".$five."%; margin: 0 2.5% 0 5%; }\n";
        echo " .col_five4 { float: left; width: ".$five."%; margin: 0 5% 0 2.5%; }\n";
        }
        echo " .columns img { width: 98% }\n";
        echo "</style>\n";
        echo '<!-- eof Magazine Columns CSS -->'."\n";
    }
}
add_action('wp_head', 'add_columns_css');

// Creates the columns quicktag button
function columns_quicktag_button() {
  if (strpos($_SERVER['REQUEST_URI'], 'post.php') ||
      strpos($_SERVER['REQUEST_URI'], 'post-new.php') ||
      strpos($_SERVER['REQUEST_URI'], 'page.php') ||
      strpos($_SERVER['REQUEST_URI'], 'page-new.php')) {
    echo '<script type="text/javascript" src="'  . get_option('siteurl') . '/wp-content/plugins/magazine-columns/js/mc.js"></script>';
    }
}

//Add the columns_quicktag_button() function to the proper admin pages
add_filter('admin_footer', 'columns_quicktag_button');
?>