Description Tag

<meta name="description" content="<?php 
if (have_posts()) : while (have_posts()) : the_post(); 
$excerp = get_the_excerpt();
$excerp = strip_tags($excerp);
if(!is_singular()) { $excerp = substr($excerp, 0, 75) ; } 
echo get_the_title().' : '.$excerp .' - ';
endwhile; endif; wp_reset_query(); ?>" />
 
<meta name="keywords" content="<?php $key_words = array();
if (have_posts()) : while (have_posts()) : the_post(); 
$categories = get_the_category();
foreach( $categories as $category) { 
  $key_words[] = $category->name;   
}
$posttags = get_the_tags();
if ($posttags) {
foreach($posttags as $tag) {
  $key_words[] = $tag->name;  
}
}
endwhile; endif; 
$key_words = array_unique($key_words);
foreach( $key_words as $words) { echo $words . ', '; }
?>" />