Add Meta Post function not working

I am using add post meta function to save some data and its not working

<?php
//include '../../../wp-blog-header.php';
$unique = "true";
$pageID = $_GET['postID'];
echo "pageID:";
echo $pageID;

echo "</br>";
$num_posts = $_GET['num_posts'];
echo "num_posts: ";
echo $num_posts;
echo "</br>";
$num_posts_meta_key = "num_posts";
add_post_meta($pageID, $num_posts_meta_key, $num_posts , $unique) or update_post_meta($pageID, "num_posts" , $num_posts);
?>

Can someone help me out?

In first page I am getting all values from textboxes or checkboxes in javascript and then i am passing it in URL to next page where add_post_meta function is there.

I tried using method POST ...but then it doesnt work for me. It just submit the page and come back w/o doing anything on 1st page. I tried with GET method..but 开发者_如何学编程nothing works.

Hence I decided to take all values like num of post, post id in javascript and then from there pass it with url by using window.location.

I am very new to wordpress plugin coding. I thought POST method in my plugin is conflicting with some other post method in post.php..not sure though..

I am writing plugin for admin panel.

not sure what your problem is.. are you sure you're passing the right postID parameter? does the post exist in the database?

You don't really need to do add_post_meta() or update_post_meta.

From the manual:

The first thing this function will do is make sure that $meta_key already exists on $post_id. If it does not, add_post_meta($post_id, $meta_key, $meta_value) is called instead and its result is returned.

<?php
// This minimum code should work, though you should really check that a post 
// with this id does exist.
update_post_meta($_GET['postID'], "num_posts" , $_GET['num_posts']);
?>