how to count the number of views in a post when a post is loaded

Hi i am new to wordpress i want to create a plugin which shows popular post. So i want to count the number of view of each post when it is loaded i have tried this but it always returns 0

add_action('template_redirect','lm_count_post');
function lm_count_post(){
 $count_key = 'post_views_count';
    $count = get_post_meta($postID, $count_key, true);
    if($count==''){
        $count = 0;
        delete_post_meta($postID, $count_key);
        add_post_meta($postID, $count_key, '0');
    }else{
        $count++;
        $x=update_post_meta($postID, $count_key, $count);
        print_r();
    }
    echo $count; //die();
}

i am not sure whether the add_action function which i gave is right or not. Any one Please help me

via Chebli Mohamed